D

Reasoning: Anterior lenticonus is a classic, highly specific ocular sign of Alport syndrome, a hereditary nephropathy that commonly progresses to end-stage renal disease in young men. The pedigree showing affected males through the maternal line fits the typical X-linked inheritance pattern of Alport syndrome, not the autosomal patterns of the other options. [Colville & Savige, 1997, PMID 9457747]