Early onset cerebellar ataxia with retained tendon reflexes: prevalence and gene frequency in an Italian population.
A genetic epidemiologic analysis of early onset cerebellar ataxias (EOCA) with retained tendon reflexes was performed in a defined area of Northwestern Italy. Forty cases diagnosed from 1940 to 1990 were ascertained. The ascertainment probability was 85.7%. The segregation analysis (Weinberg's proband method and 'singles' method under incomplete ascertainment) is compatible with autosomal recessive inheritance. The point prevalence ratio was 1.0/100,000 population. The birth incidence rate was 1/48,000 live births. Gene frequency was estimated to be 1/218. The ratio of first-cousin marriages among parents of EOCA (4.5%) was lower than expected using Dahlberg's formula (8.9%).
Chiò
A
A
II Neurological Department, University of Torino, Italy.
Orsi
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L
Mortara
P
P
Schiffer
D
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D002524:Cerebellar Ataxia / Q000453:epidemiology* / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D003241:Consanguinity; D005260:Female; D005787:Gene Frequency; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012026:Reflex, Stretch / Q000235:genetics*