GENERALDescription: Syndrome of physical and mental disorders due to chromosome 21 trisomy. The latter may be caused by the damage of the duplication or genetic material transfer. These patients have a range of disorders, from mild very serious. Prevalence: Depends on the mother’s age. Main age: Most syndromes down patients are identified at birth. Life expectancy is generally reduced. Genetics: 90% of the cases are caused by non-segregation of chromosomes resulting in trisomy, 21.5% be gene transfer, and 5% by mosaicism.Reasoning and pathogenesisCauses: No segregation of chromosome 21, resulting in two copies from one parent and one copy from the other, a total of trisomy 21. Balanced of chromosome 21q material to another chromosome (more often to 12, 13 or 15) in 90% of patients. During cell division, it is inherited independently of the normal chromosome 21s, leading to an additional genetic material. About half of these doubling cases occur for the first time. The other half have one carrier parent. Mosaicism of two cell lines: one normal and one with trisomy 21. The latter is generally related to milder clinical cases. Risk factors: Maternal age, known as carrier state (transposition/transfer), and history of chromosomal abnormality. The check which takes into consideration the mother’s age only recognizes 25% of the cases (the rest of the proportion comes from low-risk mothers).Clinical featuresSigns and symptoms:· Brachycephalism (100%)· Hypotonia at birth (80%)· Posterior the third source· Smallness and low adherence of the ears · Epicanthic folds, mongoloid eyes (90%)· Macroglossia (75%)· Low adherence to the base of the nose · Heartburn (50%)· Mental retardation (IQ= 45-50) · Abnormal dermatoglyphic features (single palmar fold, the absence of fingerprint coils on the soles Diagnostic approachDifferent diagnosis: Immunosuppression characteristics (mongoloid’s face)Related conditions: Renal and heart abnormalities, mental retardation, bowel obstruction, Hirschsprung disease and thyroiditis disease.Treatment and Evaluation Laboratory tests: If the alpha-fetoprotein checked levels to mother’s serum, between the fifteenth and twenty-second weeks of gestation (16th to 18th preferably) shows abnormally low levels the possibility of a child with Down syndrome is higher. Special tests: The karyotype must be performed for transfer control: useful in parental genetic guidance. The chorionic villus sample or amniocentesis may be performed to diagnose. Diagnostic methods: Medical history, physical examination and chromosomal analysis (pre or postpartum). (The presence of spiral on the sole generally indicates a normal child rather than trisomy).Pathological findingsPhysical disorders as described above. Alzheimer’s plaques are common after the age of twenty.Treatment Non-pharmacological. General measures: Genetic advice and evaluation of the heart function. Evaluation of the skills and assistance in daily is needed. Special measures: They depend on the patient’s needs. Parent’s guidance and support is crucial. No special diet is needed. Activity: No restriction, except if requires by heat the abnormality. Training the patient: Info brochures APO94 (Genetic disorders), APO60 (Pregnancy in mature age), AP107 (Amniocentesis and Chorionic Villus) of the American College of Obstetricians and Gynecologists. Selective drug: NoneAttendancePatient’s attendance: Child’s health maintenance, control of kidney or heart complications. Prevention/Avoidance: The re-emergence rate is 1% for real trisomy, 16-20% for transfer, and 100% for trisomy involving chromosome 12. Possible complications: Congenital heart disease (50%), bowel obstruction (10%), Hirschsprung disease (3%), thyroid disease (5-8%) and Alzheimer’s disease. Expected progress and prognosis: 1/3 of patients shoe normal growth during the first year of life. Physical and mental development slow down later. Life expectancy is reduced due to heart and other related abnormalities. The abilities of the sufferer range from being able to live and work within a protected environment if attention in a special institution is deemed necessary. Premature aging is common and life expectancy is about 50-60 years.Other issues
Pregnancy: In high danger disease due to age or other factors, Chorionic Villus Sampling should be practiced (ninth-tenth week) or amniocentesis (thirteenth-fifteenth week). The PaPPA test should be practiced at the eleventh-twelfth week. The triple test (a-fetoprotein, b-hCG, estriol) take place during the fourteenth-sixteenth week. Pregnancy is possible to Down syndrome patients, with a 50% recurrence rate (Smith, 2007).