2. Background
• Henry Turner in 1938 7 patients, who were referred to him for
dwarfism. (short stature, infertility)
• Otto Ullrich in 1930 in the German literature described "congenital
atonic-sclerotic muscular dystrophy,“
• Loss of part or all of an X , whereas gains of one or more X
chromosomes result in Klinefelter syndrome in males.
• Genes related to reproduction & cognition.
• Gonadal development and to neurocognitive alterations.
• Frequency of mosaicism range from 67% - 90%.
2
4. Genotype
• Variants of genotype
– Isochromosome
– Ring chromosome
– Mosaics
45,X
50%
46,X,i(Xq)
15%
45,X/ 46,XX, mosaics
15%
45,X/ 46,X,i (Xq) mosaics
About 5%
45,X, other X abnormality
About 5%
Other 45,X/ ? mosaics
About 5%
4
5. Phenotype
• Individuals can be more or less affected phenotypically
• Diagnosed in utero performing: amniocentesis or chorionic
villus sampling, and abnormal ultrasound findings (heart
defect, kidney abnormality, cystic hygroma, ascites, increased
nuchal translucency).
• In newborns (some have it): webbing of neck, short neck and
edema of hands and feet
• Often diagnosed during puberty because of short stature:
rarely become taller than 1.43-1.47 m (without treatment) –
SHOX gene
• Sometimes diagnosed when lack of /late onset of puberty
• Some diagnosed in relation to infertility
5
6. Phenotype
• 5-10 % have severe constriction of aorta, about 30 %
have fusion of two of the valves – operated as soon as
diagnosed
• High blood pressure
• About 30 % have malfunctioning kidneys
• Twice the risk of developing diabetes type II
• About 30% ahve a thyroid problem (hypothyroidism) –
can be treated
• Problems with learning maths and problems with spatial
perception. Sometimes language skills above average.
Normal general intelligence
6
8. In utero diagnoses
• shows early-onset signs that could be detected in the
first trimester. (cystic hygroma, fetal hydrops, cardiac defects and
increased nuchal translucency. Among heart defects, coarctation of the
aorta is the most common (44.4% of all cardial defects)
•
•
•
http://sonoworld.com/fetus/page.aspx?id=2831
Primigravida came to our department at 15 weeks of gestation. She had non-contributive family or personal history. We have seen
cystic hygroma and fetal hydrops. The amniocentesis result showed monosomy X, 45 X0. The pregnancy was terminated
afterwards.
Image 1 shows a transverse view of the fetal neck showing cystic hygroma. Image 2 shows a 3D image of the cystic hygroma
8
9. Risk and treatment
• Present in 1-2% of all conceptuses 99% of such
foetuses abort spontaneously
• Incidence between 1 in 1000 and 1 in 5000 female live
births
• Not associated with advanced maternal or paternal age
usually sporadic
• Treatment:
–
–
–
–
growth hormone supplements
estrogen therapy
progesterone therapy
Additional: echocardiography, renal ultrasonography, glucose
tolerance test
9
