A Comprehensive Overview of NF1 Mutations in Iranian Patients

Neurofibromatosis type 1 (NF1) is a genetic disorder caused by mutations in the NF1 gene. This disorder shows nearly complete penetrance and high phenotypic variability. We used the whole-exome sequencing technique to identify mutations in 32 NF1 cases from 22 Iranian families. A total of 31 variants, including 30 point mutations and one large deletion, were detected. In eight cases, variants were inherited, while they were sporadic in the remaining. Seven novel variants, including c.5576 T > G, c.6658_6659insC, c.2322dupT, c.92_93insAA, c.4360C > T, c.3814C > T, and c.4565_4566delinsC, were identified. The current study is the largest in terms of the sample size of Iranian NF1 cases with identified mutations. The results can broaden the spectrum of NF1 mutations and facilitate the process of genetic counseling in the affected families.

Genomic Landscape of Malignant Peripheral Nerve Sheath Tumor‒Like Melanoma

Malignant peripheral nerve sheath tumor (MPNST)-like melanoma is a rare malignancy with overlapping characteristics of both neural sarcoma and melanoma. Although the genomics of cutaneous melanoma has been extensively studied, those of MPNST-like melanoma have not. To characterize the genomic landscape of MPNST-like melanoma, we performed a single-center, retrospective cohort study at a tertiary academic cancer center. Consecutive patients with a confirmed histologic diagnosis of MPNST-like melanoma were screened, and those whose tissues were locally available were included in this analysis. Archival tissue from six patients (eight samples) was submitted for whole-exome and transcriptome sequencing analysis. We compared these data with available genomic studies of cutaneous melanoma and MPNST. NF1 was altered (mutated, deleted, or amplified) in 67% of patients. Genes related to cell cycle regulation were frequently altered, with frequent deletion of ZNF331, which, to the best of our knowledge, has not been previously described in cutaneous melanoma. The serine protease inhibitor SERPINB4 was deleted in 100% of the patients. We show that MPNST-like melanoma presents overlapping genomic features with cutaneous melanoma and MPNST, but it is unique by the frequency of loss of function of ZNF331 and SERPINB4.