Genotypic and Phenotypic Characteristics of Hereditary Leiomyomatosis and Renal Cell Cancer Syndrome in Korean Patients.

Background: Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant cancer predisposition syndrome. HLRCC is characterized by the development of cutaneous leiomyomas, early-onset uterine leiomyomas, and HLRCC-associated renal cell cancer (RCC) and caused by germline fumarate hydratase (FH) deficiency. We investigated the genotypic and phenotypic characteristics of Korean patients with HLRCC.

Methods: We performed direct sequencing analysis of FH in 13 patients with suspected HLRCC and their family members. A chromosomal microarray test was performed in female patients with negative sequencing results but highly suspected HLRCC. In addition, we analyzed the clinical characteristics and evaluated the genotype-phenotype correlations in Korean patients with HLRCC.

Results: We identified six different pathogenic or likely pathogenic FH variants in six of the 13 patients (46.2%). The variants included two nonsense variants, two splicing variants, one frameshift variant, and one missense variant. Of the six variants, two (33.3%) were novel (c.132+1G>C, and c.243dup). RCC and early-onset uterine leiomyoma were frequently observed in families with HLRCC, while cutaneous leiomyoma was less common. No significant genotype-phenotype correlation was observed.

Conclusions: We describe the genotypic and phenotypic spectrum in a small series of Korean patients with HLRCC. Our data reveal the unique characteristics of Korean patients with HLRCC and suggest a need for establishing an optimal diagnostic approach for them.