Leukoencephalopathia, demyelinating peripheral neuropathy and dural ectasia explained by a not formerly described de novo mutation in the SAMD9L gene, ends 27 years of investigations – a case report

BACKGROUND: Missense mutations in SAMD9L gene is associated with ataxia-pancytopenia syndrome (ATXPC), OMIM#159550. Common clinical features in these patients include neurological and hematological symptoms. The phenotype and age of onset is variable. CASE PRESENTATION: In this case report whole exome sequencing (WES) revealed a not previously reported de novo variant c.2686 T > G, p.(Phe896Val) in SAMD9L in a patient with widespread findings of slow developing pathology in the peripheral and central nervous system. The clinical picture was dominated by neurological symptoms, unlike previously described cases, and in addition dural ectasias and multiple cysts in the brain was observed using magnetic resonance imaging. CONCLUSIONS: This case underscores the effect of variable expressivity, i.e. different mutations in the same gene can cause different phenotypes.