RT Journal Article
SR Electronic
T1 Incidence, prevalence, and gene frequency studies of chronic childhood spinal muscular atrophy.
JF Journal of Medical Genetics
JO J Med Genet
FD BMJ Publishing Group Ltd
SP 409
OP 413
DO 10.1136/jmg.15.6.409
VO 15
IS 6
A1 J Pearn
YR 1978
UL http://jmg.bmj.com/content/15/6/409.abstract
AB A total population study of chronic childhood spinal muscular atrophy (arrested Werdnig-Hoffmann disease, Kugelberg-Welander disease, SMA type II and III) was undertaken in north-east England to establish gene and carrier frequencies, incidence, and prevalence. The incidence of this disease was 1 in 24 100 live births. Prevalence was 1.20 per 100,000 of the general population. A technique for estimating an autosomal recessive gene frequency in the known presence of dominant new mutations (or phenocopies), using data from a segregation analysis, is described. Gene frequency was in the range (0.00451 to 0.00659 (95% confidence limits), with a working estimate of 0.0055. Carrier rates for the autosomal recessive gene concerned were 1 in 76 to 1 in 111 (95%) confidence limits), with a working estimate of 1 in 90 for genetic counselling purposes.