Identification of a Novel Homozygous LAMB3 Mutation in a Chinese Male With Junctional Epidermolysis Bullosa and Severe Urethra Stenosis: A Case Report

This document reports on a Chinese male with intermediate junctional epidermolysis bullosa (JEB) and severe urinary tract stenosis due to a novel homozygous frameshift mutation in the LAMB3 gene [c.1172_1179delinsTGTGTGTGCAAGGAG/p. (P391Lfs*23)]. The patient exhibited symptoms such as frequent and painful urination, difficulty voiding, and had physical signs including blisters, nail dystrophies, and sparse hair. Despite various treatments for his urethral stenosis, including urethral dilatation, anterior urethroplasty with lingual mucosa, and repair with a ventral onlay penile skin flap, the patient experienced a relapse and ultimately underwent perineal urethrostomy. In contrast, his older brother, who had similar symptoms, responded positively to regular urethral dilatation. This case contributes to the understanding of the genetic basis of JEB and the challenges in managing its urological complications.