A P r a c t i c a l A p p roa c hto AmbiguousGenitalia i n t heNewborn PeriodSarah M. Lambert, MDa, Eric J.N. Vilain, MD, PhDb,Thomas F. Kolon, MDa,* KEYWORDS Ambiguous genitalia Congenital adrenal hyperplasia Disorders of sex development NeonatesCHAPTER characterize DSD and subcategories included male pseudohermaphrodite, female pseudoher-The evaluation and management of a newborn maphrodite, and true hermaphrodite. These termswith ambiguous genitalia must be undertaken used gender in the nomenclature and were oftenwith immediacy and great sensitivity. The pediatric considered controversial or disparaging. There-urologist, endocrinologist, geneticist, and child fore a revised nomenclature was proposed thatpsychiatrist or psychologist should work closely incorporated genetic etiology and descriptivewith the family in pursuing a dual goal: to establish terminology while removing gender references.4the correct diagnosis of the abnormality and, with The main categories include sex chromosomeinput from the parents, determine gender based DSD, 46,XX DSD, and 46,XY DSD. Some condi-on the karyotype, endocrine function, and tions can be placed into more than one category.anatomy of the child. In this section the authors Additionally, although the majority of infants withoutline a practical approach to the neonate born 46,XX DSD will be diagnosed with congenitalwith a disorder of sex development (DSD). adrenal hyperplasia (CAH), only approximately 50% of children with 46, XY DSD will have a defin-Nomenclature itive clinical diagnosis.5Genital ambiguity in the neonate has beendescribed for centuries and evidence for disorders Diagnosisof sexual differentiation exists from many ancientcivilizations.1 The actual incidence of DSD is diffi- Chromosomal sex is established at fertilizationcult to accurately determine because of the and the undifferentiated gonads subsequentlyheterogeneity of the clinical presentation and the develop into either testes or ovaries. A child’svaried etiologies. Using birth registries, some phenotypic sex results from the differentiation ofauthors have attempted to estimate the incidence internal ducts and external genitalia under theof ambiguous genitalia at birth; The estimated inci- influence of hormones and transcription factors.dence of clinically detectable ambiguous genitalia Any discordance among these processes resultsat birth in Germany is 2.2 per 10,000 births.2 in ambiguous genitalia or DSD. Currently, theCongenital adrenal hyperplasia is estimated to main categories of DSD are 46,XX DSD, 46,XYoccur in approximately 1 per 16,000 births.3 DSD, sex chromosome DSD, ovotesticular DSD,Historically, the term intersex was used to and 46,XX testicular DSD. urologic.theclinics.com a Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine, 39th Street and Civic Center Boulevard, Philadelphia, PA 19104, USA b David Geffen School of Medicine at UCLA, 695 Charles Young Drive South, Los Angeles, CA 90095, USA * Corresponding author. E-mail address: email@example.com Urol Clin N Am 37 (2010) 195–205 doi:10.1016/j.ucl.2010.03.014 0094-0143/10/$ – see front matter ª 2010 Elsevier Inc. All rights reserved.
196 Lambert et al 46,XX disorder of sex development CAH resulting in genital ambiguity in boys is dis- Girls with 46,XX DSD, the most common DSD, are cussed in detail later in this article. ¨ 46,XX with normal ovaries and Mullerian deriva- The most common cause of CAH is inactivation tives. The sexual ambiguity is limited to masculin- of CYP21, which catalyzes the conversion 17-OH ization of the external genitalia that occurs as progesterone to 11-deoxycortisol, a precursor of a result of exposure to androgens in utero. cortisol, and the conversion of progesterone to de- Congenital adrenal hyperplasia (CAH), which oxycorticosterone, a precursor of aldosterone. A accounts for the majority of patients with 46,XX spectrum of phenotypes from mild to severe clito- DSD, describes a group of autosomal recessive romegaly is possible. Classic 21a-hydroxylase disorders that arises from a deficiency in one of deficiency is comprised of two forms of CAH: five genes required for the synthesis of cortisol a severe, salt-wasting type with a defect in aldo- (Fig. 1). These five genes and the enzymes they sterone biosynthesis and a simple, virilizing type encode are include CYP21: 21-hydroxylase; with normal aldosterone synthesis. A mild, non- CYP11: 11b-hydroxylase, 18-hydroxylase and classic form also exists that can be asymptomatic 18-oxidase; CYP 17: 17a-hydroxylase and 17,20 or associated with signs of postnatal androgen lyase; 3b2HSD: 3b–hydroxysteroid dehydroge- excess.9 There are two CYP11 genes: CYP11B1 nase; and StAR: side chain cleavage enzyme. and CYP11B2. CYP11B1 converts 11-deoxycorti- Although these biochemical defects are character- sol to cortisol.10,11 Alternatively, CYP11B2 ized by impaired cortisol secretion, only defi- converts deoxycorticosterone (DOC) to cortico- ciencies in CYP21 and CYP11 are predominantly sterone, corticosterone to 18-hydroxycorticoster- masculinizing disorders, and 3b2HSD to a lesser one, and 18-hydroxycorticosterone to extent. Although the female fetus is masculinized aldosterone. Hypertension, which occurs in about because of overproduction of adrenal androgens two thirds of patients, is presumptively a conse- and precursors, the affected boys have no genital quence of excess DOC, with resultant salt and abnormalities. In contrast, 3b2HSD, CYP17, and water retention. Excess androgen secretion in ute- StAR deficiencies block cortisol synthesis and ro masculinizes the external genitalia of the female gonadal steroid production. Thus, boys have fetus. After birth, untreated male and female varying degrees of undermasculinization, whereas neonates progressively virilize and experience girls generally have normal external genitalia.6–8 rapid somatic growth and skeletal maturation. Cholesterol Side chain cleavage 17 hydroxylase 17,20Lyase Dehydroepiandrosterone Pregnenolone 17-OH Pregnenolone 3 HSD 3 HSD 3 HSD 17hydroxylase 17,20Lyase Progesterone 17-OH Progesterone Androstenedione 21α hydroxylase 21α h ydroxylase 17β HSD Deoxycorticosterone 11-Deoxycortisol Testosterone 11β hydroxylase 11β hydroxylase 5α reductase Corticosterone Cortisol Dihydrotestosterone aldosterone synthetase 18-OH Corticosterone aldosterone synthetase Aldosterone Fig. 1. The steroid biosynthetic pathway.
Practical Approach to Ambiguous Genitalia Newborn 197 3b2HSD catalyzes three reactions: pregneno- ovary on the contralateral side. Furthermore, thelone to progesterone; 17-OH pregnenolone to external genitalia are ambiguous with hypospa-17-OH progesterone; and dehydroepiandroster- dias, cryptorchidism, and incomplete fusion ofone (DHEA) into androstenedione.6,8 Complete the labioscrotal folds. The genital duct differentia-deficiency of 3b2HSD impairs synthesis of adrenal tion in these patients generally follows that of thealdosterone and cortisol, and gonadal testos- ipsilateral gonad on that side, such as a fallopianterone and estradiol. These newborns have severe tube with an ovary and a vas deferens withCAH and exhibit signs of mineralocorticoid and a testis.15glucocorticoid deficiency in the first week of life.Masculinization occurs as a result of DHEA 46,XY disorder of sex developmentconversion to testosterone in fetal placenta and The 46,XY DSD is a heterogeneous disorder inperipheral tissues manifesting as mild to moderate which testes are present but the internal ductsclitoromegaly. system or the external genitalia are incompletely CYP17 also catalyzes three reactions: pregneno- masculinized. The phenotype is variable andlone to 17-OH pregnenolone, 17-OH pregnenolone ranges from completely female external genitaliato dehydroepiandrosterone, and progesterone to to the mild male phenotype of isolated hypospa-17-OH progesterone.8 Phenotypically, affected dias or cryptorchidism. The 46,XY DSD can begirls have normal internal and external genitalia, classified into eight basic etiologic categories: (1)but demonstrate immature sexual development Leydig cell failure, (2) testosterone biosynthesisbecause of an inability of the ovaries to secrete defects, (3) androgen insensitivity syndrome, (4)estrogens at puberty. In mild defects, aldosterone ¨ 5a-Reductase deficiency, (5) persistent Mulleriansecretion may be normal and hypertension duct syndrome, (6) primary testicular failure orabsent.12 vanishing testes syndrome, (7) exogenous insults, StAR deficiency, also called lipoid adrenal and (8) gonadal dysgenesis.hyperplasia, is a rare form of CAH and represents Leydig cell failure The presence of testosterone,the most severe genetic defect in steroidogenesis. produced by testicular Leydig cells, inducesStAR deficiency is associated with severe gluco- male differentiation of the wolffian ducts andcorticoid and mineralocorticoid deficiencies external genitalia. The 46,XY DSD can result frombecause of a failure to transport cholesterol from Leydig cell unresponsiveness to human chorionicthe outer to the inner mitochondrial membrane, gonadotrophin hormone (hCG) and luteinizingwhich blocks conversion of cholesterol to preg- hormone (LH). The phenotypes of these patientsnenolone.13 These children are at risk for neonatal vary from normal female to hypoplastic externaldemise because of missed adrenal crisis. male genitalia.Neonates suspected to have adrenal insufficiencyshould be closely monitored for hypoglycemia, hy- Testosterone biosynthesis enzyme defects Desc-ponatremia, and adrenal insufficiency. Affected ribed earlier in this article for 46,XX DSD, defectsgirls demonstrate normal internal and external in four of the steps of the steroid biosyntheticgenitalia. Most of these women undergo sponta- pathway from cholesterol to testosterone mayneous puberty but are at risk for irregular menses, also produce genital ambiguity in the male.7,8ovarian cysts, and premature menopause.14 These defects include the less common forms of congenital adrenal hyperplasia: 3b2HSD defi-Ovotesticular disorder of sex development ciency, CYP17 deficiency, StAR protein deficiency,Ovotesticular DSD requires expression of ovarian and 17bHSD deficiency. Although DHEA conver-and testicular tissue. The most common karyotype sion into testosterone results in virilization inin the United States is 46,XX, although 46,XY, females, this same process insufficiently masculin-mosaicism, or chimerism (46,XX/46,XY) can occur. izes affected boys. Thus, male infants exhibitAlthough mosaicism may occur from chromo- ambiguous genitalia with variable degrees of hypo-somal nondisjunction, chimerism may result from spadias, cryptorchidism, penoscrotal transposi-a double fertilization (an X and a Y sperm) or tion, and a blind vaginal pouch. Boys with CYP17from fusion of two fertilized eggs. This fairly deficiency display a developmental spectrumuncommon condition can be further classified from the normal female phenotype to the ambig-into three groups: lateral ovotesticular DSD has uous hypospadiac male phenotype.12,16 Thea testis on one side and an ovary on the contralat- magnitude of the decreased masculinization ineral (usually left) side; bilateral ovotesticular DSD the male infant correlates with the severity of thehas an ovotestis on each side; and, most block in 17a-hydroxylation. Affected boys withcommonly, unilateral ovotesticular DSD has an StAR deficiency have severe testosterone defi-ovotestis on one side and either a testis or an ciencies and exhibit female external genitalia with
198 Lambert et al a blind vaginal pouch.17,18 No surviving patients (MIS), is secreted by the Sertoli cells from the with 46,XY have demonstrated testis function at time of fetal seminiferous tubule differentiation puberty. The affected 46,XY boys with 17bHSD until puberty. MIS binds to a receptor in the deficiency have external female genitalia, inguinal ¨ mesenchyme surrounding the Mullerian ducts testes, internal male ducts, and a blind vaginal before 8-weeks gestation causing apoptosis and pouch. At puberty, these patients demonstrate an regression of the Mullerian duct.25 Because the ¨ increase in their levels of gonadotropins, andro- ¨ diagnosis of persistent Mullerian duct syndrome stenedione, estrone and testosterone. Delayed viri- (PMDS) is often made at the time of inguinal hernia lization may ensue if some testosterone levels repair or orchiopexy, this syndrome is commonly approach the normal range.19,20 referred to as hernia uteri inguinalis. PMDS can occur from a failure of the testes to synthesize or Androgen insensitivity syndrome The broad secrete MIS because of an AMH gene mutation spectrum of androgen insensitivity syndrome or from a defect in the response of the duct to (AIS) ranges from patients with 46,XY with MIS because of an AMH2 receptor gene mutation. complete AIS, or testicular feminization, to partial PMDS is inherited in a sex-linked autosomal AIS. This syndrome is the result of mutations of recessive manner and AMH mutations are most the steroid-binding domain of the androgen common in Mediterranean or Arab countries with receptor resulting in receptors unable to bind high rates of consanguinity.26 Most of these androgens or receptors that bind to androgens familial mutations are homozygous and the but exhibit qualitative abnormalities and do not patients have low or undetectable levels of serum function properly. This disorder affects 1 in MIS. In contrast, AMH2 receptor mutations are 20,000 live male births with a maternal inheritance often heterozygous and are more common in pattern, because the androgen receptor gene is France and Northern Europe. These patients located on the long arm of the X chromosome.21 usually have high-normal or elevated MIS The external genitalia of a child with complete concentrations.27 androgen insensitivity resembles normal female genitalia although the karyotype is XY and testes Congenital anorchia Congenital anorchia or van- are located internally. These children are raised ishing testes syndrome encompasses a spectrum as girls. Most children are not diagnosed until of anomalies resulting from cessation of testicular puberty during an evaluation for primary amenor- function.28 A loss of testes before 8-weeks gesta- rhea. Occasionally, it is also discovered that at tion results in patients with 46,XY with female the time of inguinal hernia repair, or more recently, external and internal genitalia and either no when the prenatal karyotype does not match the gonads or streak gonads. A loss of testes at 8 to external phenotype of the newborn child. 10 weeks in development leads to ambiguous 5a-reductase deficiency 5a-reductase deficiency genitalia and variable ductal development. A loss was first described as pseudovaginal perineal of testis function after the critical male differentia- scrotal hypospadias.22 In this autosomal recessive tion period, which is at 12- to 14-weeks gestation, condition, patients have a defect in the conversion results in a normal male phenotype externally of testosterone to dihydrotestosterone (DHT). along with anorchia internally. Sporadic and These patients have a 46,XY karyotype and familial forms of anorchia exist. The familial cases, ambiguous external genitalia but normally differ- including some reports of monozygotic twins, entiated testes with male internal ducts. However, support the presence of an as yet unidentified at puberty, significant virilization occurs as testos- mutant gene in some patients with the syndrome. terone levels increase into the adult male range while dihydrotestosterone remains disproportion- Exogenous source Exogenous insults to normal ately low. There are three genetic isolates of this male development include maternal ingestion of disorder that have been described: the Dominican progesterone or estrogen or various environmental Republic, the New Guinea Samba Tribe, and in hazards. As early as 1942, Courrier and Jost29 Turkey. Many of these patients undergo a change demonstrated an antiandrogen effect on the of their gender identity from female to male after male fetus induced by a synthetic progestagen, puberty.23,24 Virilization can be secondary to and more recently, Silver and colleagues30 slightly increased plasma DHT levels and to the showed an increased incidence of hypospadias chronic effect of adult T levels on the androgen in male offspring conceived by in vitro fertilization. receptor. They hypothesized that the increased risk may be secondary to maternal progesterone ingestion. ¨ Persistent Mullerian duct syndrome Antimullerian ¨ Sharpe and Skakkebaek31 have further postulated ¨ hormone (AMH), or Mullerian inhibitory substance that the increase in reproductive abnormalities in
Practical Approach to Ambiguous Genitalia Newborn 199men is related to an increase in the in utero expo- a benign growth, is the most common tumor.38sure to environmental estrogens. Because of the 20% to 25% age-related risk for malignant transformation into a dysgerminoma,39Gonadal dysgenesis surgical removal of the gonad is recommended.Dysgenetic 46,XY DSD exhibits ambiguous devel- Patients with a 45,XX/46,XY karyotype and normalopment of the internal genital ducts, the urogenital testis biopsy could retain the testis if it is de-sinus and the external genitalia. Dysgenetic testes scended or can be placed in the scrotum. Thesecan result from mutations or deletions of any of the children would then need a close follow-up of thegenes involved in the testis determination testis by monthly self examinations for tumorcascade, namely SRY, DAX, WT1, and SOX9. formation.The SRY gene is a single exon gene located onthe short arm of the Y chromosome.32 SRY gene Sex chromosome disorder of sex developmentmutations usually result in complete gonadal Sex chromosome anomalies comprise anotherdysgenesis and XY sex reversal or Swyer category of DSD. Klinefelter syndrome (47,XXY)syndrome. The DSS locus (dosage-sensitive sex usually becomes evident during adolescence asreversal) has been mapped to the Xp21 region, patients develop gynecomastia, variable androgenwhich contains the DAX1 gene. Duplication of deficiency, and small atrophic testes with hyaliniza-the DSS locus has been associated with dysge- tion of the seminiferous tubules. These patientsnetic 46,XY DSD. The DSS locus has been theo- demonstrate azoospermia and increasing gonado-rized to contain a wolffian inhibitory factor, which tropin levels. Boys with 47,XXY may developacts as an inhibitory gene of the testis determina- through nondisjunction of the sex chromosomestion pathway.33 Swain and colleagues34 have during the first or second meiotic division in eithershown that DAX1 antagonizes SRY action in parent, or less commonly, through mitotic nondis-mammalian sex determination. Male patients junction in the zygote at or after fertilization. Thesewith Denys-Drash syndrome have ambiguous abnormalities almost always occur in parents withgenitalia with streak or dysgenetic gonads, normal sex chromosomes. The 46,XY/47,XXYprogressive nephropathy, and Wilms tumor. Anal- mosaicism is the most common form of the Kline-ysis of these patients revealed heterozygous felter variants. The mosaics, in general, manifestmutations of the Wilms tumor suppressor gene a much milder phenotype than patients with classic(WT1) at 11p13.35 The WAGR syndrome (Wilms Klinefelter. Testes differentiation and a lack oftumor, aniridia, genitourinary abnormalities, ovarian development in these patients indicatesmental retardation) is also associated with WT1 that a single Y chromosome with SRY expressionalterations.29 The urogenital anomalies seen in is enough for testis organogenesis and male sexthe WAGR syndrome are usually less severe than differentiation in the presence of as many as fourin Denys-Drash syndrome. The SOX9 gene has X chromosomes in some patients with Klinefelter.been associated with campomelic dysplasia, an These testes are not truly normal, however, sinceoften lethal skeletal malformation with dysgenetic they are usually small and azoospermic. Although46,XY DSD.36 Affected 46,XY children have there are sporadic reports of paternity, most fertilephenotypic variability from normal boys to normal Klinefelter individuals have sex chromosomegirls, depending on the function of the gonads. mosaicism.40–42 Pure gonadal dysgenesis (PGD) Swyer syndrome represents an uncommon form describes a 46,XX or 46,XY child with streakof pure gonadal dysgenesis. These children have gonads or more commonly, a child with Turnerfemale external genitalia and have a uterus and fal- syndrome (45,XO or 45,XO/46,XX).lopian tubes, however, the karyotype is 46,XY witha Y chromosome that usually does not work and 46,XX testicular disorder of sex developmenttwo dysgenetic gonads in the abdomen.37 Categories of 46,XX testicular DSD include boys Partial gonadal dysgenesis refers to disorders with classic XX with apparently normal pheno-with partial testicular development, including types, boys with non-classic XX with some degreemixed gonadal dysgenesis, dysgenetic male pseu- of sexual ambiguity, and XX ovotesticular DSD.43dohermaphroditism, and some forms of testicular Eighty percent to ninety percent of boys withor ovarian regression. Mixed or partial gonadal 46,XX result from an anomalous Y to X transloca-dysgenesis (45,XX/46,XY or 46,XY) involves tion involving the SRY gene during meiosis. Ina streak gonad on one side and a testis, often dys- general, the greater the amount of Y-DNA present,genetic, on the other side. Patients with a Y chro- the more virilized the phenotype. Although 8% tomosome in the karyotype are at a higher risk than 20% of boys with XX have no detectable Ythe general population to develop a tumor in the sequences, including SRY, about 1 in 20,000streak or dysgenetic gonad. Gonadoblastoma, phenotypic boys have a 46,XX karyotype. Most
200 Lambert et al of these patients have ambiguous genitalia, but 2 cm in a term male neonate.47–50 One should reports of boys with classic XX without the SRY describe the position of the urethral meatus and gene do exist.26,33,38,39,43,44 This phenomenon the amount of penile curvature and note the again raises the possibility of mutation of a down- number of perineal orifices. stream wolffian inhibitory factor when cases of Another critical finding on physical examination normal virilization are seen without the presence is the presence of a uterus that is palpable by of the SRY gene. Some patients with 46,XX testic- digital rectal examination as an anterior midline, ular DSD have the SRY gene translocated from the Y cord-like structure. Of course, a thorough general to the X chromosome. However, for most patients, physical examination must also be performed. A the genes responsible are not yet identified.45,46 blood pressure should be taken to rule out hyper- tension. The presence of hyperpigmentation should also be documented. Dysmorphic features History and Physical Examination indicating syndromic manifestations (eg, short Patients with bilaterally impalpable testes or broad neck, widely spaced nipples, or aniridia) a unilaterally impalpable testis and hypospadias should also be noted. should be regarded as having DSD until proven otherwise, whether or not the genitalia appear Patient Evaluation ambiguous. Patient history should include the In the immediate newborn period, all patients degree of prematurity, ingestion of exogenous require a karyotype and laboratory evaluation by maternal hormones used in assisted reproductive serum electrolytes, 17-OH progesterone, testos- techniques, and maternal use of oral contracep- terone, luteinizing hormone, follicle stimulation tives during pregnancy. A family history should hormone, and urinalysis. The karyotype can be be obtained to document any urologic abnormali- determined from peripheral blood or skin fibro- ties, neonatal deaths, precocious puberty, amen- blasts from genital skin. It is important to remember orrhea, infertility, or consanguinity. Any abnormal that chromosomal studies from an amniocentesis virilization or cushingoid appearance of the child’s do not negate the need for a postnatal karyotype. mother should also be noted. Abnormalities of the Once the karyotype is determined, serum analysis prenatal maternal ultrasound are also helpful, such will assist in narrowing the differential diagnosis. If as discordance of the fetal karyotype with the the 17-OH progesterone level is elevated, a diag- genitalia by sonogram. nosis of CAH can be made. Determining the 11-de- For differential diagnosis and treatment oxycortisol and deoxycorticosterone levels will purposes, the most important physical finding is help differentiate between 21-hydroxylase and the presence of one or two gonads. If no gonads 11b-hydroxylase deficiencies. If the levels are are palpable, all DSD categories are possible. Of elevated, then a diagnosis of 11b-hydroxylase defi- these, 46,XX DSD is most commonly seen fol- ciency can be made, whereas low levels confirm lowed by 45,X/46,XY. A palpable gonad is highly 21-hydroxylase deficiency. If the 17-OH proges- suggestive of a testis, or rarely, an ovotestis, terone level is normal, a testosterone to DHT ratio because ovaries and streak gonads do not along with androgen precursors before and after descend. If one gonad is palpable, 46,XX DSD is hCG stimulation will help elucidate the 46,XY DSD less likely, whereas 45,X/46,XY, ovotesticular etiology. A testosterone to DHT ratio of greater DSD, and 46,XY remain possibilities. If two gonads than 20 is suggestive of a 5 alpha reductase defi- are palpable, 46,XY, and rarely ovotesticular DSD, ciency. A failure to respond to hCG in combination are the most likely diagnoses (Fig. 2). with elevated LH and FSH levels is consistent with Patients should be examined in a warm room anorchia. It is important to remember that for the supine in the frog leg position with both legs free. first 60 to 90 days of life, a normal gonadotropic It is important to determine size, location, and surge occurs with a resultant increase in the testos- texture of both gonads, if palpable. The unde- terone level and its precursors. During this specific scended testis may be found in the inguinal canal, time period, hCG stimulation for androgen evalua- the superficial inguinal pouch, at the upper tion can be postponed. Serum levels of AMH and scrotum, or rarely in the femoral, perineal, or inhibin B can also be measured in the immediate contralateral scrotal regions. One should also postnatal period to document the existence of note the development and pigmentation of the la- normal testicular tissue. bioscrotal folds along with any other congenital anomalies of other body systems. An abnormal Genetic Tests phallic size should be documented by width and stretched length measurements. Micropenis is The initial genetic testing is the assessment of the defined as a stretched penile length of less than chromosomes by karyotype. This testing can be
Practical Approach to Ambiguous Genitalia Newborn 201 Palpate Gonads 0 1 2 FPH DSD 46XX Partial Gonadal Dysgenesis MGD 46XYMPH DSD GD D Ovotesticular DSD TH Ovotesticular DSD (rare) TH (rare) 46XY DSD PH 46XY DSD MPH Ovotestesticular DSD H Electrolytes, 17OH-Progesterone, Testosterone, LH FSH Karyotype Pelvic Ultrasound Genitogram (possible) 17OH Progesterone (2000ng/dl) Testosterone NL 17OH Progesterone uterus Testosterone uterus seen +/- uterus, NL Testosterone ovaries Laparoscopy, Gonad Biopsy 2 testes 46X X DSD HCG stimulation: (CAH) (CAH) pre/post: 46XX 46X X DSD 46XX Testosterone/DHT (maternal virilizing maternal virilizing synd DHEA/androstenedione syndrome) 11 deoxycortisol DOC testis streak M PH 46XY DSD ovary 46XY 46XY ovotestis (46XX) (46XX) 45X/46XY) (45X/46XY) 11 deoxycortisol 11 deoxycortisol DOC DOC Ovotesticular DSD TH Gonadal 1. 5a reductase def iciency 46XX 46XX Dysgenesis 2. AIS (46XX/XY) 3. Steroid deficiency-male CAH 46X X DSD 46X X DSD (46XY) 4. Dysgenetic testes 21 Hydroxylase 11 Hydroxylase (45X/46XY) 5. Primary testicular failure PURE (S-S) PARTIAL (S-T) deficiency deficiency Pur e 45X 45X/46XY 6. Leydig cell failure 45X/46XX (46XY) 7. PMDS 46XX (45X/46XY)Fig. 2. Anatomic and endocrine approach to DSD evaluation. NL, normal; S, streak gonad; T, testis.done by regular, meta-phasic, karyotype, but if the If the DSD does not have an obvious geneticquestion asked is limited to the nature of the sex cause, whether it is syndromic or isolated, a screenchromosomes, an interphasic FISH (fluorescent for CNVs (micro-deletions or micro-duplications) isin situ hybridization) should be performed with X- recommended. This screen is performed in clinicaland Y-specific probes, providing the number of laboratories using micro-array–based compara-and the quality of sex chromosomes in less than tive genomic hybridization (CGH) methods.48 hours. If a mosaic is detected or suspected, Although the techniques and the sensitivity of thea large number of interphasic nuclei can be as- array vary, all methods detect CNVs that cansessed by FISH (typically 200–300) to evaluate then be confirmed by FISH. For best sensitivity,the percentage of each clone accurately (Fig. 3). oligonucleotide-based arrays are preferred, and The follow-up genetic tests are diagnostic. They may detect CNVs as small as 10 to 50 kb. Theare of two kinds: one is the direct sequencing of use of direct molecular sequencing and array-a specific gene and the other the evaluation of CGH is presented in the diagnostic algorithmcopy number variants (CNV) by micro-array anal- shown in Fig. 1. The interpretation of geneticysis. If there are enough phenotypic features to testing can be challenging. If the test detects pointorient the physician toward a specific diagnosis, mutations or CNVs known to cause a DSD, thedirect sequencing of the causal gene is preferred. genetic diagnosis is certain, and the testing ofThis sequencing would typically happen in cases parents as potential carriers will then be performedof complete androgen insensitivity, or congenital for the purpose of genetic counseling.adrenal hyperplasia, for which the diagnostic indi- If the test detects unknown point mutations orcators are strong. Several genes can be sequenced CNVs, the investigation of parental DNA becomeson a clinical basis by molecular laboratories (eg, AR, essential. A de novo (not present in parents) CNVCYP21, SRY, SOX9, SF1), and the list is growing. or point mutation in patients with a DSD is likely
202 Lambert et al Fig. 3. (A) Genetic evaluation of XY patient with masculinized genitalia. AMHR, Anti-Mullerian Hormone Receptor; CYP11A1, Cytochome p450scc; CYP17, 17a-hydroxylase; HSD3B2, 3b-Hydroxysteroid dehydrogenase 2; HSD17B3, 17b-hydroxysteroid dehydrogenase3; Nml, normal; POR, P450 Oxidoreductase; US, Ultrasound. (B) Genetic evaluation of XX patient with masculinized genitalia. (Data from Fleming A, Vilain E. The endless quest for sex determination genes. Clin Genet 2005;67(1):15–25).
Practical Approach to Ambiguous Genitalia Newborn 203to be causative. An inherited, unknown variant thoughtfully and carefully construed to the family.(present in one of the parents) is more difficult to A team approach that includes family discussionsinterpret and requires a specialized genetics should begin immediately. The importance ofconsultation. In all cases, pre- and post-test a clinical psychologist or psychiatrist who isgenetic counseling is essential to ensure that the familiar with DSD cannot be underestimated. Infamily understands the interpretation of the test addition to support from the medical team, manyand the risk for recurrence in future pregnancies. families find support groups useful.55 Although the preferred gender assignment is notRadiographic Tests always clear, a thorough examination of endocrine function, karyotype, and potential for fertilityExamination of the internal genital can be achieved should guide the determination. Current DSDusing many modalities, including abdominal and guidelines recommend that all individuals receivepelvic ultrasound, MRI, fluoroscopy, endoscopy, a gender assignment in infancy and family partici-or laparoscopy. Noninvasive, quick, and inexpen- pation in that decision-making process is essen-sive, an ultrasound should be the first radiologic tial.4 A single-institution survey of parents of girlsexamination obtained. Although only 50% accu- with CAH reported that 52% of respondentsrate in detecting intra-abdominal testes,51 ultra- were completely satisfied with the informationsound can detect gonads in the inguinal region they were given during the neonatal period, ¨and can assess Mullerian structures. For example, whereas 43% were only partially satisfied.56 This ¨the presence of Mullerian structures visible on study reinforces the need for open and directa pelvic ultrasound can often differentiate between communication between the family and medicalpure gonadal dysgenesis and complete AIS in an team as a core component of satisfactory patientadolescent with primary amenorrhea.52 Although care. This sentiment is confirmed by a survey ofmore expensive, MRI scan can further delineate fellows in the urology section of the Americanthe anatomy. Ectopic gonads, testes, and imma- Academy of Pediatrics that documented that theture ovaries have an intermediate signal intensity overwhelming majority of pediatric urologistson T-1 weighted images and a high signal intensity believe a team approach and parental involvementwith an intermediate signal intensity surrounding are recommended and important in the care ofrim on T-2 weighted images.53 A genitogram patients with DSD.57 The decision of whether orshould be performed to evaluate a urogenital not to pursue surgical intervention should besinus, including the entry of the urethra in the based upon anatomy, functional status, andvagina and the presence of a cervical impres- a consensus of opinion between the family andsion.51 Infants with intra-abdominal or non- medical team; this decision must be individualizedpalpable testes in whom ovotesticular DSD; for each patient with DSD.45,X/46,XY DSD; or 46,XY DSD is considered willrequire an open or laparoscopic exploration withbilateral deep longitudinal gonadal biopsies for REFERENCEShistologic evaluation, which will determine the 1. 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