All are true about Down syndrome except:

Ans: D (Hypo...) [Ref: Nelson 18th/508; OPG 7th/613; 6th/ 592; Robbins 7th /176-77; Radiology Review Mnuai by Wolfgang Danhert 5th/925}Systemic ab norma lilies in Down syndrome# GIT : Duodenal, ileal andjejunal atresia. tracheoesophogeal fistula, hirsprung's disease, meckel's diverticulum, imperforate anus, omphalocle.# Eye : Brushfield ed risk of cataract, nystagmus and squint.# CVS : Endocardial cushion defect (MC), VSD, Ostium primum ASD & AV valve malformation.# Hearing defects : Serous otitis media;conductive &''or sensorineural hearing loss Nelson 18th/508.#Thyroid-dysfunction: Hypothyroidism.# Atlanto- occipital dislocation/subluxation.# Malignancy : ed risk of AML and ALL# Early onset Alzheimer disease# Abnormal immune responseTABLE (Nelson 18th/508} Chromosomal Trisomies and Their Clinical FindingsSyndromeIncidenceClinical ManifestationsTrisomy 21 Down syndrome1/600-800 birthsHypotonia, flat face, upward and sian ted palpebral fissures and epicanthic folds, speckled irises (Brush field sports);varying degrees of mental and growth retardation ; dysplasia of the pelvis, cardiac malformations, and simian crease; short, broad hands, hypoplasia of middle phalanx of 5th finger, duodenal atresia, and high arched palateTable (Nelson 18th/508): Additional Disorders in Children with Down SyndromeDuodenal atresiaAnnular pancreasTracheoesophageal fistulaHirschsprung diseaseShort statureShort sternumBrachycephalyDelayed fontanel closureThree fontanelsFrontal sinus hypoplasiaPeripheral joint laxityAtlantoaxial instability (C1-C2 subluxation)Exaggerated space between 1st and 2nd toesMottled skin in infancyDry coarse skin in adolescenceIncreased Risk for Development of Leukemia: AML, ALL