Familial late-onset focal dystonia in an African American family

• Recent studies of THAP1 (DYT6) have pointed out that late-onset focal dystonia can have a genetic basis. Familial late-onset primary dystonia has not been described in African- Americans. Six members of an African American family were affected by focal or segmental dystonia with a mean age at onset of 47 years (range, 45-50). Two additional individuals with milder clinical signs were classified as probably affected. Clinical phenotypes included cervical, laryngeal and handforearm (writer's cramp) dystonia, following an autosomal dominant mode of inheritance. TOR1A (DYT1) and THAP1 (DYT6) were screened for sequence variants. There were no abnormalities in TOR1A. A novel THAP1 sequence variant (c.-237-3G>T) was found in both affected and unaffected family members and did not co-segregate with dystonia. This variant was also found in 1/212 African American control alleles. Another variant at the same site (c.-237-3G>A) was found in 2/212 African American control alleles and one African American subject with laryngeal dystonia (1/84 alleles). Therefore, these variants are unlikely to be pathogenic. Familial late-onset primary dystonia does occur in non-Caucasian populations. Future studies of THAP1 and other dystonia genes must take genetic background into consideration.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Medicinsk genetik (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Medical Genetics (hsv//eng)

Nyckelord

alprazolam

African American

focal dystonia

dystonia

allele

segmental dystonia

onset age

Caucasian

writer's cramp

autosomal dominant inheritance

spasmodic dysphonia

inheritance

population

gene

phenotype

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kon (ämneskategori)

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