2Approximately one in 1000 live births. IncidenceApproximately one in 1000 live births.
3GeneticsTrisomy 21 (47, +21), - 94 %, The frequency of trisomy increases with increasing maternal age.Robertsonian translocation involving chromosome 21- Approx. 3-4 %, not related to maternal age.Trisomy 21 mosaicism – 2 to 3 % cases
8Clinical Features Extremities Head and neck Brachycephaly Up-slanting palpebral fissuresEpicanthal foldsBrushfield spotsFlat nasal bridgeFolded or dysplastic earsOpen mouthProtruding tongueShort neckExcessive skin at the nape of neckExtremitiesShort broad handsShort fifth fingerIncurved fifth fingerTransverse palmer creaseSpace between first and second toeHyper flexibility of joints
11Neonatal features Flat facial profile Poor Moro reflex Excessive skin at the nape of neckSlanted palpebral fissuresHypotoniaHyper flexibility of jointsDysplasia of pelvisAnomalous earsDysplasia of midphalanx of fifth fingerTransverse palmer crease
13Mental Retardation Almost all DS babies have MR. Mildly to moderately retarded .Starts in the first year of life.Average age of sitting(11 mon), and walking (26 mon) is twice the typical age.First words at 18 months.IQ declines through the first 10 years of age, reaching a plateau in adolescence that continues into adulthood.
14Heart Disease 50 % of Down Syndrome pts have heart disease Atrioventricular septal defectVSDSecundum ASDPDATetrology of FallotMitral valve prolapseAR, MR
15GI abnormalities 5% of cases Duodenal atresia or stenosis, sometimes assoc with annular pancreas in 2.5 % of casesImperforate anusEsophageal atresia with TE fistula is less commonHirschsprung’s diseaseStrong assoc with celiac disease b/w 5 – 16 % , 5 – 16 fold increase as compared to general population
16Growth BW, length and HC are less in DS Reduced growth rate Prevalence of obesity is greater in DSWeight is less than expected for length in infants with DS, and then increases disproportion ally so that they are obese by age 3-4 yrs
18Eye problems Most common disorders are Refractory error – 35 to 76 percentStrabismus – 25 to 57 percentNystagmus – 18 to 22 percentCataract occur in 5 % of newborns.Frequency increases with age.
19Hearing loss Unilateral or bilateral Conductive, sensorineural or mixedOtitis media is a frequent problem
20Hematologic disorders The risk of leukemia is 1 to 1.5 percent.65% of newborn have polycythemia resulting in hypoglycemia.Risk of AML and ALL is also much higher than the general population.Transient leukemia – exclusively affects NB.- It is asymptomatic with spontaneous resolution in 2-3 months.- Vesiculopustular skin eruptions are common and resolve with disorder.
21Endocrine disorderThyroid disease – Hypothyroidism occurs more frequently than hyperthyroidism.Diabetes – The risk of type 1 diabetes is three times greater than that of the general population.
22Reproduction Women with DS are fertile and may become pregnant. Nearly all males with DS are infertile. The mechanism is impairment of spermatogenesis
23Atlantoaxial instability Excessive mobility of atlas (C1) and the axis (C2), may lead to subluxation of the cervical spine.Diagnosis made by lateral neck radiograph.Patients are advised to avoid contact sports.
24Sleep apneaObstructive sleep apnea is more common.
26Diagnosis Prenatal screening If no screening – It is recognized from the characteristic phenotypic features.Confirmed by Karyotype.
27Management1. Growth – Measurements should be plotted on the appropriate growth chart for children with DS.This will help in prevention of obesity and early diagnosis of celiac disease and hypothyroidism.2. Cardiac disease – All newborns should be evaluated by cardiac ECHO for CHD in consultation with pediatric cardiologist.3. Hearing – Screening to be done in the newborn period, every 6 months until 3 yrs of age and then annually.
28Management (cont.)4. Eye disorders - An eye exam should be performed in the newborn period or at least before 6 months of age to detect strabismus, nystagmus, and cataracts.5. Thyroid Function – Should be done in newborn period and should be repeated at six and 12 months , and then annually.6. Celiac Disease – Screening should begin at 2 yrs. Repeat screening if signs/Sx develop.
29Management ( cont)Hematology – CBC with differential at birth to evaluate for polycythemia as well as WBC.Atlanto-axial instability – X ray for evidence of AAI or sub-luxation at 3 to 5 years of age.Alzheimer’s disease – Adult with a Down Syndrome has earlier onset of symptoms. When diagnosis is considered, thyroid disease and possible depression should be excluded.
30MortalityMedian age of death has increased from 25 yrs in 1983 to 49 yrs in 1997, an average of 1.7 yrs increase per year.Most likely cause of death is CHD, Dementia, Hypothyroidism and Leukemia.Improved survival is because of increased placements of infants in homes andchanges in treatment for common causes of death.Survival is better for males and blacks.
31Counseling May begin when a prenatal diagnosis is made. Discuss the wide range of variability in manifestation and prognosis.Medical and educational treatments and interventions should be discussed.Initial referrals for early intervention, informative publications, parent groups, and advocacy groups.