A novel variant in the FLCN gene in a Chinese family with Birt–Hogg–Dubé syndrome

Background This study aimed to identify disease‐causing variants within a Chinese family affected by Birt–Hogg–Dubé syndrome (BHDS), which arises from an autosomal dominant inheritance pattern attributed to variants in the folliculin (FLCN) gene, recognized as a tumor suppressor gene. Methods A Chinese proband diagnosed with BHDS due to renal tumors underwent next‐generation sequencing (NGS), revealing a novel variant in the FLCN gene. Sanger sequencing was subsequently performed on blood samples obtained from family members to confirm the presence of this variant. Results A novel germline frameshift variant (NM_144997.5:c.977dup) was identified in five individuals among the screened family members, marking the first report of this variant. Additionally, a somatic frameshift variant (NM_144997.5:c.1252del) was detected in the renal tumors of the proband. No variant was detected in unaffected family members. Conclusions A novel heterozygous variant was identified in exon 9 of the FLCN gene, which broadens the spectrum of FLCN variants. We recommend that molecular analysis of the FLCN gene be performed in patients with suspected BHDS and their families. In a BHD‐associated renal tumors Chinese family. A novel heterozygous variant (NM_144997.5:c.977dup) was identified in exon 9 of the FLCN gene, which broadens the spectrum of FLCN variants. We recommend that molecular analysis of the FLCN gene be performed in patients with suspected BHDS and their families.