Rebecca Foulger Added comment: Comment on list classification: Updated rating from Grey to Green: Gene added to panel by Zornitza Stark. 1 Green expert review (by Zornitza) plus 4 unrelated cases in literature supporting variants in HPCA causing AR dystonia. Note that HPCA variants are a rare cause of AR dystonia.
Rebecca Foulger commented on gene: HPCA: Although two independent studies (PMID:27771228 and PMID:27145302) from 2017 and 2016 failed to support the role of HPCA in pathogenesis of dystonia, this is most likely because HPCA variants represent a rare form of dystonia.
Rebecca Foulger commented on gene: HPCA: Atasu et al. 2018 (PMID:30145809) revealed two unlreated consanguineous Turkish families with complex dystonia and novel HPCA variants (p.W103* and p.P10PfsTer80). The first family started to suffer involuntary head movements at age 8 months, and official examination at age 20 revealed dystonia. The second family developed dystonia of lower limbs age 17.
Rebecca Foulger commented on gene: HPCA: In 3 siblings (age 61, 57 and 51) from consanguineous Sephardic Hewish family with dystonia (MIM:224500) which presented in their first decade, Charlesworth et al, 2015 (PMID:25799108) identified a homozygous missense variant in HPCA (N75K). Sequencing of HPCA in samples from 150 additional patients with early-onset dystonia (<30 years old) identified compound heterozygous missense variants (T71N and A190T) in a 64 year old woman of Sri Lankan origin with the disorder. The woman reported dystonia onset in her late-teens to early twenties. Her unaffected siblings contained one or both wild-type alleles supporting pathogenicity of the compound heterozygous variants in the affected individual.