Whole-exome sequencing to identify novel mutations of nevoid basal cell carcinoma syndrome in a Chinese population.

BACKGROUND: Nevoid basal cell carcinoma syndrome (NBCCS) is a rare autosomal dominant disease with a complex genetic etiology. Although three causative genes (PTCH1, PTCH2, SUFU) have been identified through linkage analysis and Sanger sequencing, the genetic background of NBCCS hasn't been fully understood. METHODS: We performed a whole-exome sequencing (WES) in a Han Chinese NBCCS family and two unaffected volunteers to search for its causative gene. Bioinformatic analysis was used to select candidate genes and analyze the functional networks of each candidate gene. RESULTS: A total of 8 single-nucleotide variants (SNVs) were detected in PTCH1, PTCH2 and SUFU in all the 5 subjects, however none of them was considered the pathogenic genetic mutation in this NBCCS family. The following filtering process identified 17 novel candidate genes (GBP3, AMPD1, ASPM, UNC5C, RBM46, HSPA1L, PNPLA1, GPR126, AP5Z1, ZFHX4, KIF24, C10orf128, COX15, GPRC5A, UGGT2, RHBDF1, RPUSD1). Among them ZFHX4 had been already identified as a new basal cell carcinoma susceptibility loci through a genome-wide association study (GWAS) and was considered the most likely pathogenic gene for this NBCCS family. The functional network analysis revealed that ZFHX4 may be involved in notch signaling pathway. CONCLUSIONS: Our study reported the identification of 17 novel candidate genes in a Han Chinese family through WES. ZFHX4 may be a susceptibility gene for NBCCS in Chinese population.

A systematic review of the literature of nevoid basal cell carcinoma syndrome affecting East Asians and North Europeans.

OBJECTIVE: To compare, by systematic review, North European and East Asian consecutive case series of nevoid basal cell carcinoma syndrome (NBCCS). STUDY DESIGN: A systematic review of the literature was performed for all consecutive case series of NBCCS, which included keratocystic odontgenic tumors (KCOTs) arising in North European and East Asian communities. The clinical and radiologically apparent features were identified and synthesized, and a meta-analysis was performed. RESULTS: East Asian reports were significantly more "proband only" compared with North European reports. Significant differences between these 2 communities were observed for 5 of the 6 major features and 11 of the 27 minor features. With regard to the major NBCCS features, the North Europeans displayed significantly more frequent basal cell carcinomas, calcified falx cerebri, palmar and plantar pits, and a family history, whereas the East Asians displayed KCOTs significantly more frequently. With regard to minor features, East Asians displayed significantly more frequent cleft lips and palates and hypertelorism. CONCLUSIONS: East Asians displayed multiple KCOTs and cleft lips and palates more frequently compared with North Europeans.

Clinical and oral findings in an Afro-Brazilian family with Gorlin-Goltz syndrome: case series and literature review.

Gorlin-Goltz syndrome (GGS) seems to be unusual in black persons. The authors present an Afro-Brazilian family case report of GGS. The main complaint of the index case was a painless swelling of the left mandible, which was diagnosed as an odontogenic keratocyst. Further classical features of the Syndrome were present in this patient. Other two family members were diagnosed as cases of GGS and one of them presented 11 clinical findings characteristic of the syndrome. From the three cases reported, two of them presented five major diagnostic criteria for the GGS, and the diagnosis was only made because of an oral complaint. This case series emphasizes the importance of carefully examining the patient and close relatives for signs of GGS, even if they belong to an ethnic group in which this diagnosis is unusual.

PTCH1 gene mutations in Keratocystic odontogenic tumors: a study of 43 Chinese patients and a systematic review.

BACKGROUND: The keratocystic odontogenic tumor (KCOT) is a locally aggressive cystic jaw lesion that occurs sporadically or in association with nevoid basal cell carcinoma syndrome (NBCCS). PTCH1, the gene responsible for NBCCS, may play an important role in sporadic KCOTs. In this study, we analyzed and compared the distribution pattern of PTCH1 mutations in patients with sporadic and NBCCS-associated KCOTs. METHODS: We detected PTCH1 mutations in 14 patients with NBCCS-associated KCOTs and 29 patients with sporadic KCOTs by direct sequencing. In addition, five electronic databases were searched for studies detecting PTCH1 mutations in individuals with NBCCS-associated or sporadic KCOTs, published between January 1996 and June 2013 in English language. RESULTS: We identified 15 mutations in 11 cases with NBCCS-associated KCOTs and 19 mutations in 13 cases with sporadic KCOTs. In addition, a total of 204 PTCH1 mutations (187 mutations from 210 cases with NBCCS-associated and 17 mutations from 57 cases with sporadic KCOTs) were compiled from 78 published papers. CONCLUSIONS: Our study indicates that mutations in transmembrane 2 (TM2) are closely related to the development of sporadic KCOTs. Moreover, for the early diagnosis of NBCCS, a genetic analysis of the PTCH1 gene should be included in the new diagnostic criteria.

PTCH germline mutations in Chinese nevoid basal cell carcinoma syndrome patients.

OBJECTIVES: PTCH, the human homologue of the Drosophila segment polarity gene, patched, has been identified as the gene responsible for nevoid basal cell carcinoma syndrome. The aim of this study was to investigate PTCH gene mutation in Chinese patients with nevoid basal cell carcinoma syndrome. MATERIALS AND METHODS: DNA was isolated from both odontogenic keratocyst tissue and peripheral blood of five patients with syndrome and one patient with only multiple odontogenic keratocysts, and mutational analysis of the PTCH gene performed by direct sequencing after amplification of all 23 exons by polymerase chain reaction (PCR). RESULTS: A previously reported germline mutation (c.2619C>A) was identified in two familial cases involving the mother and the daughter, with the mother also carrying a novel somatic mutation (c.361_362insGAGC). Three novel germline PTCH mutations (c.1338_1339insGCG, c.331delG and c.1939A>T) were detected in three unrelated patients with syndrome. The patient with multiple odontogenic keratocysts who failed to fulfill the diagnostic criteria of the syndrome also carried a novel germline mutation (c.317T>G). CONCLUSION: The frequent germline PTCH mutations detected in our series provide further evidence for the crucial role of PTCH in the pathogenesis of nevoid basal cell carcinoma syndrome in Chinese.

Multifocal desmoplastic medulloblastoma in an african-american child with nevoid basal cell carcinoma (gorlin) syndrome. Case report.

The authors present the case of a 2.5-year-old African-American boy with desmoplastic medulloblastoma (MB) and nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin syndrome, an autosomal dominant disorder resulting from mutations in the patched (PTCH) gene that predisposes to neoplasias (including basal cell carcinomas [BCCs] and MB) and to widespread congenital malformations. The diagnosis of NBCCS was suspected based on the clinical examination, patient and family medical histories, and histopathological characteristics of the tumor. Radiotherapy was withheld. The diagnosis of NBCCS was confirmed by DNA testing, which revealed a novel mutation in the PTCH gene. This is the first report of an African-American child with MB diagnosed with NBCCS prior to radiotherapy. Although only a small number of patients with MB have NBCCS, the diagnosis must be considered because radiotherapy in such patients can lead to the formation of BCCs and other intracranial neoplasms within the irradiated field. This case emphasizes the importance of obtaining thorough family and patient medical histories and of carefully examining the patient and close relatives for signs of NBCCS to avoid the potentially devastating consequences of missing this diagnosis.

Nevoid basal cell carcinoma syndrome in a person with dark skin.

The expression of basal cell carcinoma tumors of the skin is blunted in individuals with dark skin and nevoid basal cell carcinoma syndrome. The occurrence of multiple basal cell carcinomas in these patients is a relatively rare finding. We describe a 25-year-old man of partial African-American descent with constitutive Fitzpatrick type IV pigmented skin and the clinical stigmata of nevoid basal cell carcinoma syndrome including histopathologic evidence of 11 basal cell carcinomas.

Mutations in the human homologue of the Drosophila patched gene in Caucasian and African-American nevoid basal cell carcinoma syndrome patients.

The nevoid basal cell carcinoma syndrome (NBCCS), or Gorlin syndrome, is a multisystem autosomal dominant disorder. The salient features of this syndrome include multiple basal cell carcinomas, palmar and/or plantar pits, odontogenic keratocysts, skeletal and developmental anomalies, and ectopic calcification. Other features include such tumors as ovarian fibromas and medulloblastomas. There is extensive interfamilial as well as intrafamilial variability with respect to the manifestation and severity of the phenotype. Alterations in the human homologue (PTCH) of the Drosophila segment polarity gene patched have been identified in NBCCS patients as well as tumors associated with this syndrome. We report several mutations in this gene in NBCCS patients and present the clinical phenotypes of the individuals in whom these mutations were identified.