TRISOMY 21
Trisomy 21 is the first and best known example of autosomal trisomy in man. This is also known as G Trisomy, Mongolism and or Down Syndrome.
The manifestations consist mainly of physical abnormalities and mental retardation as a result of developmental defects. The name of the syndrome is derived from the obliquely set, slanting eyes that most patients present.
In our Textbooks in Pediatrics by Dr Fe del Mundo, it is stated there that Lejeune et al, first showed in 1959 that the condition is caused by trisomy of a chromosome belonging to the G group, specifically chromosome 21. The additional No. 21 is presumed to be the result of non disjunction during the meiotic process in the parental usually the maternal gamete since the condition is more frequent among infants of ageing mothers.
The risk of Down syndrome according to maternal age based on the data of Carter and McCarthy is as follows:
Age of mother. Risk
Years. Per preg
< 29. 1:3000
30-34. 1:600
35-39. 1:280
40-44. 1: 70
45-49. 1: 40
All mothers. 1:565
In population
The following features are commonly seen in this condition:
– brachycephaly
– flattened occiput
– small bony orbits
– lateral upward slant of the eyes
– epicanthus
– strabismus
– protruding fissured tongue
– short nose with flat bridge
– abnormally aligned teeth
– broad and square hands and feet
– clinodactyly of the little finger and increased spaces between first and second fingers and toes
– single transverse palmar crease
– short broad neck
Children with Down syndrome do not present gross changes in the central nervouse system. Their mental status, as observed, is often trainable and able to comprehend.
Almost all of those who have reached school age are active, friendly, happy, affectionate and music loving.
Let us continue to respect, to love and to give utmost importance to children with special needs.