Segmental Hyperkeratotic/Verrucous Venous Malformation in a Neonate With a KRIT1 Pathogenic Variant

Familial cerebral cavernous malformation (FCCM) is a rare autosomal dominant disorder marked by venous malformations of the central nervous system. Cutaneous involvement occurs in fewer than 10% of cases and typically presents as hyperkeratotic or angiokeratoma-like plaques, most often associated with pathogenic variants in KRIT1 , CCM2 , or PDCD10 . We describe a neonate from Northern New Mexico, where the KRIT1 Common Hispanic Pathogenic Variant (c.1363C>T, p.Gln455Ter) is highly prevalent, who presented at birth with a congenital, ulcerated segmental purpuric plaque and violaceous papules. Histopathology and GLUT1 positivity were consistent with a verrucous venous malformation within the phenotypic spectrum of FCCM. Targeted genetic testing confirmed a heterozygous KRIT1 variant. This case expands the cutaneous spectrum of FCCM and underscores the value of early molecular diagnosis in neonates with atypical vascular anomalies, especially in regions with a known founder effect.