Angiokeratoma corporis diffusum with severe acroparesthesia, an endothelial abnormality, and inconspicuous genetic findings

Angiokeratoma corporis diffusum (ACD) was long thought to be a specific dermal sign of Fabry disease (FD, X-linked alpha-galactosidase A [GLA] deficiency). However, other lysosomal storage diseases (LSDs) have also been identified as triggers of ACD. Generalized vasculopathy is an important pathogenetic factor in FD and may also lead to the acroparesthesia (AP) often predominant in FD. We report on an 85-year-old woman with ACD present since her youth and associated with severe AP. Ultrastructure of the dermal lesion showed no lysosomal involvement, but the absence of the basement membrane of the endothelial cells of the capillary vessels was noteworthy. Repeated analyses of the GLA gene revealed no evidence of FD. Whole-exome sequencing was negative for FD and other LSDs, and allowed us to also study FD-related intronic regions of the GLA gene. This is the first report of a patient with FD-like ACD with an endothelial abnormality, otherwise unexplained vasculopathy and severe AP, which are not due to FD or another LSD. Based on family history, another genetic, yet unidentified, defect may cause the disease in this patient. In unexplained ACD, extended genetic analysis is required to exclude particular pathogenic variants of the GLA gene and other genes.