Moderate and mild mental retardation in the Martin-Bell syndrome.
A survey of children attending schools for the moderately or the mildly mentally handicapped has shown that two out of 25 boys and two out of 22 girls with idiopathic moderate mental retardation had the Martin-Bell syndrome, while none of 75 boys and one out of 51 girls with mild mental retardation were FRAXA positive. Consideration of these figures along with published studies suggests that 7% of moderate and 3.8% of mild idiopathic mental retardation in boys, and 2.5% of moderate and 3.3% of mild idiopathic mental retardation in girls may be due to the Martin-Bell syndrome.