1、 先天愚型先天愚型 Fu Jun FenChildrens Hospital of Zhejiang University School of MedicineF CONTENTSF Patterns of inheritanceFChromosomal AbnormalitiesDefinition:Abnormal chromosome number and abnormal chromosomal arrangements may lead to multiple congenital anomalies.Down syndrome is the most common autosoma
2、l chromosomal anomaly(1/700).1846,Sequin,1866,Down,1959,Lejeune It is an important cause of mental retardation and congenital anomalies.The occurrence of trisomia 21 increases with advancing maternal age(35 yr).FIntroductionFKaryotypes and PhenotypesStandard:about 95%have trisomies of chromosome 21,
3、Translocation:2.5-5%D/G:Mosaic:2-4%of individual are mosaic with some normal cells.Down syndrome girl Down syndrome babyFClinical manifestations Varying degrees of mental and growth retardationCharacteristic face:flat small face,upward and slanted palpebral fissures and epicanthic folds,low set ears
4、,outstanding tongue,high and narrow plate,flat nasal bridgeDysplasia of the pelvis,cardiac malformation,simian crease,short broad hand,joint hyperflexibilityThe turn down or flap at the top of the ear The single line across the hand and the pinkie finger turned inward.The fingers are somewhat shorte
5、rSpread toes especially between large toe hypotoniaThe single line across the handJoint hyperflexibilityFPrevent and treatmentAvoid close relative marriagePrenatal diagnosis and genetic analysis (maternal and fetal serum,amniotic fluid and cell,chorionic villus,ultrasound,fluorescent insitu-hybridiz
6、ation，FISH)Complication Treatment Education Down Syndrome Net Ring Understanding the gift of the life FIntroduction FEtiology In the neonate and infant:Characteristic face with enlarged,protruding tongueIn the childhood and adolescent Clinical picture is fully developed FDiagnosis Thyroid screeningLaboratory TestBone X-ray FDifferentiate Diagnosis Down syndromeRickets(Vitamin D deficiency)Mucopolysaccharidosis Type I Congenital chondrodysplasiaGrowth hormone deficiency BH4 BH2F F F F F F
