Accumulating evidence suggests that inherited melanoma is not rare and approx. one in seven individuals with melanoma has clinically relevant hereditable cancer-predisposing and/or -susceptibility variant(s). Concerning its germline genetic background, genetic screening aims to identify either variants of predisposing genes with high penetrance or variants of susceptibility genes with medium or low penetrance. However, less attention is paid to genetic testing of germline variants of genes influencing patients’ survival outcomes or enhancing the design of new therapies. We aimed to investigate whether the germline genetic background of a Hungarian melanoma cohort (n = 17) contains any pathogenic or likely pathogenic variants of the BRCA2, POLE, WRN, FANCI, PALB2, and RAD54B genes and if the presence of these variants correlate with the clinical findings of the patients, including the advanced stage of melanoma, poor prognosis, and poor survival. We identified three novel variants in the FANCI gene and one novel variant in the RAD54B gene. We detected rapid disease progression, unfavorable outcome, and therapeutic resistance in the patient carrying the likely pathogenic FANCI variant. Our study highlights the importance of screening germline variants of genes influencing melanoma progression, therapy resistance, and survival of patients.
Autosomal dominant non-syndromic hearing loss (ADNSHL) is a genetically heterogenic condition. The transformation/transcription domain associated protein (TRRAP) gene has been recently associated with ADNSHL, and only four variants of the gene have so far been reported in this disease. Here, we report on a Hungarian ADNSHL family in which the affected individuals exhibited sensorineural hearing loss with similar clinical symptoms, including initial impaired high frequencies that subsequently affected speech and lower frequencies. Whole exome sequencing and screening of the shared genetic variants of the affected individuals was performed. Our results revealed a novel heterozygous missense variant (NM_001244580.2, c.5360A>G, p.Lys1787Arg) in the TRRAP gene. This variant is completely co-segregated with hearing impairment. It is present in a heterozygous form in the affected mother and daughter but not carried by any unaffected family members. This study highlights the importance of elucidating the germline genetic background of ADNSHL, which may help to predict individual risk and the risk of family members. This will improve prevention, screening, and therapeutic measures for each patient and hearing loss-prone families.
Basal cell nevus syndrome (BCNS, OMIM 109400) is a familial cancer syndrome characterized by the development of numerous basal cell cancers and various other developmental abnormalities, including epidermal cysts of the skin, calcified dural folds, keratocysts of the jaw, palmar and plantar pits, ovarian fibromas, medulloblastomas, lymphomesenteric cysts, and fetal rhabdomyomas. BCNS shows autosomal dominant inheritance and is caused by mutations in the patched 1 (PTCH1) gene and the suppressor of the fused homolog (SUFU) gene. In a few cases, variants of patched 2 (PTCH2) have been found in patients who met the criteria for BCNS. In an investigation of 11 Hungarian families who fulfilled the diagnostic criteria for BCNS, whole-exome sequencing (WES) and multiplex ligation-dependent probe amplification (MLPA) identified two novel pathogenic variants (c.2994C>A; p.Cys998Ter and c.814_818del; p.Asn272SerfsTer11), one recently identified variant (c.1737_1745del p.Val580_Val582del), and three recurrent disease-causing variants of the PTCH1 gene with a diagnosis rate of 63.6%. Disease-causing variants were not found for the SUFU and PTCH2 genes. These applied methods could not fully elucidate the genetic background of all the BCNS cases that we investigated. To uncover the missing heritability of BCNS, whole-genome sequencing or an epigenetic approach might be considered in the future.
A MECP2-duplikációs szindróma (Lubs-féle mentális fejlődési zavar) X-kromoszómához kötött öröklődésmenetet mutató ritka kórállapot, amely hemizigóta fiúkban mindig előidéz klinikai tüneteket, míg az eltérést hordozó nők általában tünetmentesek, bár ritkán a nőkben is kialakulhatnak változatos súlyosságú tünetek. Az általunk vizsgált 6 éves leány genetikai konzíliumát mozgás- és beszédfejlődésben észlelt elmaradás miatt kérte a gyermekneurológus szakorvos. A proband kislány kromoszómavizsgálata normál női karyotypust mutatott. A P245 microdeletiós szindrómára specifikus 1A-próbamixszel végzett multiplex ligatiofüggő próbaamplifikációs (MLPA-) vizsgálat az Xq28 kromoszomális régióban a MECP2-4b, MECP2-3, valamint MECP2-1 próbák területén heterozigóta duplikációt jelzett. Az Xq28 kromoszomális régióra specifikus fluoreszcens in situ hibridizációs (FISH-) vizsgálat során nem tapasztaltunk duplikációt. A családtagok közül a beteg egészséges leánytestvére és édesapja, valamint leány féltestvére nem bizonyult MLPA-vizsgálattal MECP2-duplikációsnak. A tüneteket mutató édesanyánál a proband genotípusával megegyező eltérést azonosítottunk. Az édesanya újabb párkapcsolatából fogant várandósságában elvégzett magzati MLPA-vizsgálat a fiúmagzatban kimutatta a családban azonosított MECP2-duplikációt, a kariotipizálás pedig 21-triszómiát mutatott. A várandós nő a két egymástól független magzati kórállapot miatt kérte a terhesség megszakítását. Az általunk bemutatott eset tanulsága, hogy nem tisztázott fejlődési elmaradással jelentkező páciensek esetén a G-sáv-technikával elvégzett karyotypus-elemzés megfelelő MLPA-vizsgálattal történő kiegészítése segíthet a genotípus-fenotípus összefüggések felállításában és genetikai diagnózis esetén a praenatalis diagnosztika megszervezésében. Orv Hetil. 2024; 165(1): 30–34.
Malignant melanoma is a complex malignancy with genetic, environmental, and lifestyle factors in its etiology. While germline variants in melanoma predisposition genes have been described, many patients remain genetically unexplained after panel testing. We previously analyzed a Hungarian melanoma cohort (n = 17), identifying variants in predisposing or susceptibility genes in 58.82% of patients. For individuals negative on this melanoma-specific panel, we expanded testing to a 19-gene panel associated with multiple cancer types. Next-generation sequencing was performed, followed by Sanger sequencing for confirmation. Variants were classified according to ACMG guidelines. In a 58-year-old female patient with a history of primary cutaneous melanoma, we identified a novel heterozygous frameshift variant in the tumor suppressor gene OBSCN (c.21322_21323insCTGG, p.G7108AfsTer10; NM_001386125.1). This insertion introduces a premature stop codon in exon 89 within the immunoglobulin-like domain, predicting protein truncation. Classified as likely pathogenic (PVS1, PM2), the variant is absent from population databases. To date, somatic OBSCN mutations have been reported in melanoma. This first report of a germline OBSCN frameshift variant in melanoma expands the genetic landscape of melanoma predisposition and suggests that OBSCN may represent a candidate gene contributing to melanoma risk.