Edward syndrome is?
Ans. B. Trisomy 18. (Ref OP Ghai 7th /pg. 614)EDWARD SYNDROME (Trisomy 18)# Although much rarer than Down syndrome (trisomy 21), it is the 2nd commonest autosomal trisomy, more common than Patau syndrome (trisomy 13)# Incidence: 1 in 3500 and 1 in 7000.# It is also associated with increased maternal age.# Of the affected infants some 80-90 % die within the first week usually from cardiopulmonary failure.# A few cases have been reported surviving into the teens, but they were all found profoundly retarded.- Features* Obstetrics: There is often polyhydramnios and IUGR, single umbilical artery.* Head Neck: Cranium is long and narrow with prominent occiput (strawberry shaped) and cystic hygroma (not commonly seen though, esp when compared to Turner's syndrome).* Face: Ears are low set and underdeveloped, (hypotelorism). Abnormal facies with micrognathia and narrow sloping palpebral fissures and Facial cleft.* Hands: Clenched hands; 2nd and 5th fingers overlapping the 3rd and 4th fingers. (>60%, characteristic)* Other flexion deformities may also be there. Hypoplastic nails.* Arms: Shortened radial ray.* Foot: Rocker bottom feet, clubbed foot.* GIT (common):Intestinal atresias, malabsorption, T-0 fistula, thin diaphragm and diaphragmatic hernia, omphalocele and exomphalos.* Renal: Renal hypoplasia/cystic dysplasia, PCKD, horseshoe kidney, PUJ obstruction.* Heart: VSD, complete AV canal, DORV.* Ocular: Hypotelorism.* Neural tube defects: Holoprosencephaly, choroid plexus cyst, small cerebellum with prominent cistema magna, myelomeningocele.Patau (trisomy 13):Incidence1:5,000 births.OBSSevere IUGR, hydramnios.CNSMicrocephaly, Alobar holoprosencephaly, posterior encephalocele, scalp defect, neural tube defect.FaceMidline labial cleft (Cleft lip & palate), proboscis, hypotelorism, cyclopia, anophthalmia, small earsEyesMicrophthalmos; anophthalmos; cyclopia in some cases; dysgenesis of anterior segment (iris hypoplasia, iris adhesions, chamber angle abnormalities); corneal opacities; congenital glaucoma; cataracts; persistent hyperplastic primary Vitreous; retinal dysplasia; colobomas of iris, ciliary body, fundus; intraocular cartilage, optic nerve hypoplasia.SkeletonPostaxial polydactyly, rocker bottom feet.HeartVSD, echogenic chorde tendinae, hypoplastic ventricle, TOF, transposition.KidneyPCKD, horseshoe kidney.GlOmphalocele (occasionally)D/dMeckel Gruber syndromeAdditional Educational points:# Trisomy-21 is Down syndrome.# Deletion of short arm of 5th chromosome is Cri-du-Chat syndrome.# Patients with following disease are at higher risk of developing leukemia = Down syndrome, Klinefelter's syndrome, Patau syndrome, excessive chromosomal fragility syndromes like Fanconi's anemia, Bloom syndrome, ataxia telangiectasia, and Kostmann syndrome).
Trisomy 13
Trisomy 18
Trisomy 21
Trisomy 20
Genetics And Genetic Disorders