Autosomal recessive genes.

1. Hereditary & Genetic
Diseases
Exam Roll No.: 33,34,35,36,37
B.V.Sc&A.H, 9th Sem

2. Introduction
• Genetic disease is an illness caused by abnormalities in genes or chromosomes,
which are quite rare.
• A genetic disease may or may not be heritable disease as some genetic disorders are
passed down from the parent’s genes.
• The most common inheritance pattern of genetic disease is as a simple recessive
trait.
• They are mostly tissue specific i.e.
1. Skeletal
2. Central Nervous System
3. Blood
4. Skin
5. Muscle
6. Ophthalmic

3. Genetic diseases of Cattle & Buffalo
• Chondrodysplasia
• Chondrodysplasia is a congenital anomaly
related to defects of the genes that control the
chondrogenesis.
• Main feature is reduced length of bones with an
endochondral growth pattern. Sometime death
of fetus and abortion may result.
• Complex Vertebral Malformation(CVM)
• CVM is a lethal malformation syndrome,
observed in late term aborted fetuses and
perinatal calves. Characterized by growth
retardation and bilateral flexure of the carpal
and metacarpophalangeal joints along with
rotation of digits.

4. • Osteogenesis Imperfecta(OI)
• OI is a congenital collagenopathy of type 1 collagen which is the most
abundant and ubiquitous collagen which constitutes an important
component of bonnes, tendons, ligament, skin and teeth in
mammals.
• Osteopetrosis( Marble bone)
• It is a fatal autosomal recessive genetic defect in which calves are
born 10-30 days early. They show head abnormalities that consist of
brachygnathia inferior, impacted molars and a protruding tongue.
• The long bones are shorter along with marrow cavities filled with
unabsorbed bone, but are very fragile and can be broken easily.

5. • Syndactylism
• Also known as mule foot ,characterized by
malformation of distal parts of one or
more limbs by complete or partial fusion
or non division of the functional digits.
• Weaver Syndrome
• Also known as bovine progressive
degenerative myloencephalopathy. It is
most commonly observed in Brown Swiss.
• Cattle experience weakness and lack of
coordination in all four limbs and have an
odd weaving gait while trying to walk.

6. .
• Spinal Muscular Atrophy
• It is a progressive lethal autosomal recessive disease
and is inherited as an autosomal recessive disorder.
• Characterized by severe muscular atrophy,
progressive quadriparesis and sternal recumbency.
Death due to atrophy of respiratory muscles leading
to respiratory failure.
• Bovine Leukocyte Adhesion Deficiency(BLAD)
• BLAD is an autosomal recessive congenital
immunological disorder in which animal are prone to
recurrent and prolonged mucosal and epithelial
infections. Widespread ulcerative and necrotizing
stomatitis, periodontitis, loss of teeth and alveolar
periostitis, extensive dermatophytosis are observed.
• Hematological changes in combination with stunted
growth are the other clinical signs.

7. • Congenital Erythropoietic Porphyria(CEP)
• CEP is hereditary enzyme deficiency in the pathway of haeme
biosynthesis.
• Most prominent lesion is photosensitization, which may cause
subepidermal blistering and dermal necrosis of unpigmented areas.
• Citrullinemia
• It is an unusual Holstein and Holstein Friesian specific disorder leading
to enzymatic disruption of the urea cycle .
• It causes ammonemia and related neurological signs. Affected calves
present with ataxia, aimless wandering, blindness, head pressing,
convulsions and death.

8. • Epitheliogenesis Imperfecta (EI)
• EI is an inborn malformation
characterized by localized agenesia of the
skin
• Characterized by lack of skin on distal
parts of the limbs, deformed ears due to
auricular epithelial defects, defects in the
integument of muzzle, and a defective
oral epithelium.
• Anophthalmos and Microphthalmos
• Condition in which animals are born
without eyes.
• In such animals orbit normally fails to
develop or have an abnormally small
orbit.

9. • Congenital Cataract
• Cataracts related to the genetic defects and also
some other ocular abnormalities such as retinal
detachment, aniridia, microphakia, and
hydrocephalus are observed.
• Arthrogryposis Multiplex( curly cow syndrome)
• Found in Angus cattle defect caused due to
autosomal recessive gene.
• Main signs are multiple joint contracture. Some
time abdominal hernia and cranial defect
(cranioschisis with meningocele) are found.

10. • Hydrocephalus
• Calves with hydrocephalus have excess
fluid in their brain cavities.
• Disease is prohibited by keeping
carrier bulls from breeding their
carrier females.
• Hypotrichosis
• Caused by a recessive gene it occurs in
some breed of beef cattle which is
expressed as complete or partial loss
of hair.

11. • Idiopathic Epilepsy(IE)
• It is a convulsive disorder caused by an
autosomal recessive genetic defect and
is incompatible with life.
• They usually have a normal phenotype
when they are not seizing.
• Crooked Tail syndrome
• The main clinical symptoms are
retardation of growth, increased
muscular development; tail deviation,
stocky head, short straight limbs etc.
are observed. Along with that scoliosis
and spastic paresis are found.

12. Genetic Disease of Sheep
Albinism
• Albinism, a metabolic disorder seen occasionally
in various mammalian species, has also been
described in sheep. This condition in sheep is
inherited as a simple autosomal recessive trait.
• The affected lambs exhibit pure white coat, pink
eyes, and impaired vision in bright light. These
lambs show no trace of pigment in hooves,
horns, or skin. The lambs have full vision indoors
in moderate or dim light.
Anury
• The tail-less condition in lambs is attributed to
an autosomal dominant gene.
• In heterozygous state, causes variable
hypoplasia or aplasia of the coccygeal vertebrae,
and that in homozygous state, causes death.

13. Bent-limb disease( Spider Lamb Sickness)
• Bent-limb disease, also known as
"hereditary muscle contracture."
• In the affected lambs, the forelimbs are
often bent with rigid joints, and most
cases also exhibit wry-neck leading to
dystocia.
Cerebellar Cortical Atrophy
• "daft lamb disease“ (DLD) , is a congenital
defect characterized by the inability of
the lambs to stand or walk normally
• lambs also show variable locomotor
abnormalities and a characteristic
backward arching of the neck

14. .Dermatosparaxis
• Characterized by excessive fragility of the
skin in different breeds of sheep.
• Other organs of the affected animals are
also extremely fragile, the skin is easily
torn by the hands, and severe lacerations
result from slight scratches that would
cause only minor damage to normal lambs.
Other diseases
• Cataract
• Entropion
• Glomerulonephritis
• Muscular Dystrophy
• Scrapie
• Epidermolysis Bullosa

15. Genetic Disorders of Goat
• Achondroplasia
• Achondroplasia (dwarfism) is known to occur in
different breeds of goats.
• Developmental problems of cartilages and bones
resulting in dwarfism can occur through functional
disorders of the pituitary or thyroid gland.
• Afibrinogenemia
• Congenital afibrinogenemia characterized by
severe hemorrhagic diathesis with joint bleeding
occurs in goats.
• In affected goats, bleeding time is prolonged, the
platelet adhesiveness on passage through the
glass filter is diminished, and the blood samples
are uncoagulable.

16. .• Anotia and Microtia.
• In goats, ear length is inherited as an
incompletely dominant trait. The ear lobes of the
heterozygotes are 30% of the normal length
(3.5cm versus 10.2 cm), whereas the
homozygotes show virtually no external ear
except a stub measuring less than 2 cm.
• The earless sheep are known to be deaf, although
no gross alteration is detected in the inner ear.
• Gynecomastia
• Gynecomastia has been observed in different
breeds of goats.
• the bucks are normal at birth, exhibit normal
libido, and sire kids before they begin to show
gynecomastia and spontaneous lactation (milking
buck syndrome).

17. .
• Beta-Mannosidosis
• Beta-mannosidosis is an autosomal
recessive lysosomal storage disease of goat
characterized by a deficiency of the
glucohydrolase-mannosidase.
• Clinical evidence of severe neurologic
disturbance that becomes progressively
worse with age.
• Udder Problem
• Hanging or sac-like conformation of the
udder with a meaty texture and a lateral
deviation of the teats occurs in various
breeds of goats. Absence of the teat orifice
or the teat canal and the presence of
supernumerary teats (polythelia) are also
relatively common anomalies in goats.

18. Fainting Goat
• Condition involved with
dysfunction of chloride
conductibility

19. Bent Toes and Split
Wing in Chicken
.

20. Scrotal hernia in pig. Large Umbilical hernia in pig. Atresia Ani in female
Cryptorchid (one testicle retained)
in male pig.
Hermaphrodite pig with
large clitoris
Splayleg or spraddle leg pig

21. Strategies for Controlling Genetic Diseases
• Prevent animals that carry these genes by culling.
• The bulls for natural breeding and semen for AI should be screened
for undesirable genes.
• Purchase of semen or bull from reputable breeders with detailed
pedigree.
• Early diagnosis of disease may contribute significantly to improved
animal disease control.
• If problem is inherited animal should be sent for cytogenetic and
molecular screening.
• If the cause is genetic, inform the breed association/ society and give
them a full report of the findings.
• Development of DNA based tests for all the genetic diseases will aid
to identify the diseased animals very early in life, so as to prevent
further propagation of undesirable alleles in future generations