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lip reading, and enrollment in special schools for the handicapped enable these children to compensate well for their lack of the marvelous gift of hearing. Mental Retardation Some of the most unfortunate types of congenital afflictions are those which affect the intellect. Untreated hypothyroidism (called cretinism) will inevitably result in retarded mental development, unless recognized early and treated with replacement doses of thyroid. A simple test using blood from the umbilical cord can detect this condition, which may be difficult to recognize clinically. High levels of jaundice in the newborn period may produce a condition known as kernicterus. This may provoke seizures and retardation. However, if recognized early the appropriate use of light therapy or exchange transfusion may avert any brain damage and minimize the risk. Anoxia at birth may also trigger changes in the brain that result in retarded mental productivity. Safe obstetrical practices and the prompt treatment of newborn asphyxia can minimize these hazards. Chromosome defects may cause retardation. The most common is called Down’s syndrome or Mongolism, In such cases, a chromosome (number 21), is produced in a set of three instead of one pair. This is termed Trisomy 21, Other varieties occur where the chromosomes are broken or translocated. Changes in the palmar creases, a characteristic facial appearance with squinting eyes, an unusually round face, and a peculiar smile are all associated with mental retardation. Less commonly, cardiac or other internal organ defects are seen. Special education and an unusual degree of parental care are needed to train these handicapped children. Fortunately, most of them have very pleasant dispositions and can bring joy in unusual ways to parents who are willing to change their aspirations and accept the handicap of their offspring.
Chromosome analysis can often detect specific genetic diseases.