Περίληψη:
Huntington’s disease (HD) is an autosomal dominant disorder
characterized by a triad of chorea, psychiatric disturbance and
cognitive decline. Around 1% of patients with HD-like symptoms lack the
causative HD expansion and are considered HD phenocopies. Genetic
diseases that can present as HD phenocopies include HD-like syndromes
such as HDL1, HDL2 and HDL4 (SCA17), some spinocerebellar ataxias (SCAs)
and dentatorubral-pallidoluysian atrophy (DRPLA). In this study we
screened a cohort of 21 Greek patients with HD phenocopy syndromes for
mutations causing HDL2, SCA17, SCA1, SCA2, SCA3, SCA8, SCA12 and DRPLA.
Fifteen patients (71%) had a positive family history. We identified one
patient (4.8% of the total cohort) with an expansion of 81 combined
CTA/CTG repeats at the SCA8 locus. This falls within what is believed to
be the high-penetrance allele range. In addition to the classic HD
triad, the patient had features of dystonia and oculomotor apraxia.
There were no cases of HDL2, SCA17, SCA1, SCA2, SCA3, SCA12 or DRPLA.
Given the controversy surrounding the SCA8 expansion, the present
finding may be incidental. However, if pathogenic, it broadens the
phenotype that may be associated with SCA8 expansions. The absence of
any other mutations in our cohort is not surprising, given the low
probability of reaching a genetic diagnosis in HD phenocopy patients.
Συγγραφείς:
Koutsis, G.
Karadima, G.
Pandraud, A.
Sweeney, M. G. and
Paudel, R.
Houlden, H.
Wood, N. W.
Panas, M.
