PT  - JOURNAL ARTICLE
AU  - S Bundey
AU  - A Thake
AU  - J Todd
TI  - The recurrence risks for mild idiopathic mental retardation.
AID  - 10.1136/jmg.26.4.260
DP  - 1989 Apr 01
TA  - Journal of Medical Genetics
PG  - 260--266
VI  - 26
IP  - 4
4099  - http://jmg.bmj.com/content/26/4/260.short
4100  - http://jmg.bmj.com/content/26/4/260.full
SO  - J Med Genet1989 Apr 01; 26
AB  - A genetic study of children attending ESN(M) schools in Coventry has shown a recurrence risk of idiopathic mental retardation in sibs lying between 1 in 4 and 1 in 5. There was also a prevalence of mental retardation in other relatives that was greater than the population prevalence, and was less for second degree relatives than for first degree, and less still for third degree relatives. Recurrence in sibs was greater if more than one first degree relative was affected. There was no suggestion of a contribution by X linked genes, once the fragile X syndrome had been excluded. The presence of perinatal and other environmental factors in the index children did not alter the recurrence risk for sibs except for very low birth weight. There was a low recurrence rate of mental retardation in Asian families, suggesting that they had a different distribution of intelligence from non-Asian families.