Down's syndrome

474

Smith

The Journal o[ Pediatrics March I967

9. DOWN'S SYNDROME (21 trisomy syndrome)

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101/2 months Height age: 9 months

14 months Height age: 9 months

Small stature. Pre- or postnatal onset, variable in degree Performance. Mental deficiency; I.Q. usually 25 to 50; hypotonia, tendency to protrude tongue Cranlofaclal. Flat occiput; palpebral fissures, upward lateral slant; inner epicanthic folds; speckling of iris; eyelashes short and sparse; auricles small with or without malformation Hands and feet. Clinodactyly of fifth finger; Simian creases; dermal--distal palmar axial triradius, high frequency of ulnar loops on digits, tibial arch hallucal pattern; gap a n d / o r crease between first and second toes Other. Diastasis recti; male: small genitals, with or without cardiac defect Etiology. Trisomy for all or a large part of the long arm of a G group chromosome, designated as number 21 Comment. Usually the clinical diagnosis is obvious. However, in children without clear-cut stigmas, a chromosomal study may be necessary to confirm the diagnosis. The empiric recurrence risk is about 1 per cent for all maternal age groups. Translocatlon cases comprise about 3.5 per cent of the patients and 6 per cent of those born of mothers under 30 years of age. Only about ~ of translocation cases have a carrier parent. Therefore, only about 2 per cent of patients born of mothers under 30 years of age will be found to have a translocation carrier parent REFERENCE

Smith, D. W.: Autosomal abnormalities, Am. J. Obst. & Gynec. 90: 1055, 1964.