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Gastrointestinal stromal tumors (GISTs) are common neoplasms of the gastrointestinal tract that can be treated successfully using C-kit target therapy and surgery; however, imatinib chemoresistance is a major barrier to success in therapy. The present study aimed to discover alternative pathways in imatinib-resistant GISTs. Long noncoding RNAs (lncRNAs) are newly discovered regulators of chemoresistance. Previously, we showed that the lncRNA HOTAIR was upregulated in recurrent GISTs. In this study, we analyzed differentially expressed lncRNAs after imatinib treatment and found that HOTAIR displayed the largest increase. The distribution of HOTAIR in GISTs was shifted from nucleus to cytoplasm after imatinib treatments. The expression of HOTAIR was validated as related to drug sensitivity through Cell Counting Kit-8 assays. Moreover, HOTAIR was associated strongly with cell autophagy and regulated drug sensitivity via autophagy. Mechanistically, HOTAIR correlated negatively with miRNA-130a in GISTs. The downregulation of miRNA-130a reversed HOTAIR-small interfering RNA-induced suppression of autophagy and imatinib sensitivity. We identified autophagy-related protein 2 homolog B (ATG2B) as a downstream target of miR-130a and HOTAIR. ATG2B downregulation reversed the effect of pEX-3-HOTAIR/miR-130a inhibitor on imatinib sensitivity. Finally, HOTAIR was shown to influence the autophagy and imatinib sensitivity of GIST cells in mouse tumor models. Our results suggested that HOTAIR targets the ATG2B inhibitor miR-130a to upregulate the level of cell autophagy so that promotes the imatinib resistance in GISTs.

Hepatocellular carcinoma (HCC) is an invasive malignant neoplasm with a poor prognosis. The development of chemoresistance severely obstructs the chemotherapeutic efficiency of HCC treatment. Therefore, understanding the mechanisms of chemoresistance is important for improving the outcomes of patients with HCC. Eukaryotic translation initiation factor 5A2 (eIF5A2), which is considered to be an oncogene, has been reported to mediate chemoresistance in various types of cancer; however, its precise role in HCC remains unclear. Accumulating evidence has suggested that autophagy serves a dual role in cancer chemotherapy. The present study aimed to investigate the role of autophagy in eIF5A2-mediated doxorubicin resistance in HCC. High expression levels of eIF5A2 in human HCC tissues were observed by immunohistochemistry using a tissue microarray, which was consistent with the results of reverse transcription-quantitative PCR analysis in paired HCC and adjacent healthy tissues. HCC patient-derived tumor xenograft mouse model was used for the in vivo study, and knockdown of eIF5A2 effectively enhanced the efficacy of doxorubicin chemotherapy compared with that in the control group. Notably, eIF5A2 served as a repressor in regulating autophagy under chemotherapy. Silencing of eIF5A2 induced doxorubicin sensitivity in HCC cells by triggering lethal autophagy. In addition, 5-ethynyl-2′-deoxyuridine, lactate dehydrogenase release assay and calcein-AM/PI staining were used to determine the enhanced autophagic cell death induced by the silencing of eIF5A2 under doxorubicin treatment. Suppression of autophagy attenuated the sensitivity of HCC cells to doxorubicin induced by eIF5A2 silencing. The results also demonstrated that knockdown of the Beclin 1 gene, which is an autophagy regulator, reversed the enhanced autophagic cell death and doxorubicin sensitivity induced by eIF5A2 silencing. Taken together, these results suggested eIF5A2 may mediate the chemoresistance of HCC cells by suppressing autophagic cell death under chemotherapy through a Beclin 1-dependent pathway, and that eIF5A2 may be a novel potential therapeutic target for HCC treatment.

CRISPR/Cas9 has been confirmed as a distinctly efficient, simple-to-configure, highly specific genome-editing tool that has been used to treat monogenetic disorders. Epidermolytic palmoplantar keratoderma (EPPK) is a common autosomal dominant keratin disease resulting from dominant-negative mutation of the KRT9 gene, and it has no effective therapy. We performed CRISPR/Cas9-mediated treatment on a knockin (KI) transgenic mouse model that carried a small indel heterozygous mutation of Krt9, c.434delAinsGGCT (p.Tyr144delinsTrpLeu), which caused a humanized EPPK-like phenotype. The mutation within exon 1 of Krt9 generated a novel protospacer adjacent motif site, TGG, for Cas9 recognition and cutting. By delivering lentivirus vectors (LVs) encoding single-guide RNAs (sgRNAs) and Cas9 that targeted Krt9 sequence into HeLa cells engineered to constitutively express wild-type and mutant keratin 9 (K9), we found the sgRNA was highly effective in reducing expression of the mutant K9 protein in vitro. We injected the LV into the fore-paws of adult KI-Krt9 mice three times every 8 days and found that the expression of K9 decreased ∼14.6%. The phenotypic mitigation was revealed by restoration of the abnormal differentiation and aberrant proliferation of the epidermis. Our data are the first to show that CRISPR/Cas9 is a potentially powerful therapeutic option for EPPK and other PPK subtypes. Keywords: CRISPR/Cas9, gene therapy, epidermolytic palmoplantar keratoderma, Krt9 gene (mouse), indel

// Rong-Rong Liu 1, * , Ya-Su Lv 1, * , Yue-Xiao Tang 1 , Yan-Fang Wang 1 , Xiao-Ling Chen 2 , Xiao-Xiao Zheng 1 , Shang-Zhi Xie 1 , Ying Cai 1 , Jun Yu 3 , Xian-Ning Zhang 1 1 Department of Cell Biology and Medical Genetics, Research Center for Molecular Medicine, National Education Base for Basic Medical Sciences, Institute of Cell Biology, Zhejiang University School of Medicine, Hangzhou, 310058, China 2 Department of Biological Chemistry, Zhejiang Chinese Medical University, Hangzhou, 310053, China 3 Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Key Laboratory of Multi-Organ Transplantation of Ministry of Public Health, Hangzhou, 310003, China * These authors contributed equally to this work Correspondence to: Xian-Ning Zhang, e-mail: zhangxianing@zju.edu.cn Jun Yu, e-mail: Dr.yujun@gmail.com Keywords: eukaryotic translation initiation factor 5A2, reactive oxygen species, epithelial-mesenchymal transition, migration, hepatocellular carcinoma Received: September 24, 2015 Accepted: February 28, 2016 Published: March 23, 2016 ABSTRACT Eukaryotic translation initiation factor 5A2 ( eIF5A2 ) has been identified as a critical gene in tumor metastasis. Research has suggested that reactive oxygen species (ROS) serve as signaling molecules in cancer cell proliferation and migration. However, the mechanisms linking eIF5A2 and ROS are not fully understood. Here, we investigated the effects of ROS on the eIF5A2-induced epithelial-mesenchymal transition (EMT) and migration in six hepatocellular carcinoma (HCC) cell lines. Western hybridization, siRNA transfection, transwell migration assays, wound-healing assays, and immunofluorescence analysis were used. The protein levels of eIF5A2 in tumor and adjacent tissue samples from 90 HCC patients with detailed clinical, pathological, and clinical follow-up data were evaluated. Overexpression of eIF5A2 was found in cancerous tissues compared with adjacent tissues. We found that eIF5A2 overexpression in HCC was associated with reduced overall survival. Knockdown of eIF5A2 and intracellular reduction of ROS significantly suppressed the invasion and metastasis of HCC cells. Interestingly, N1-guanyl-1, 7-diaminoheptane (GC7) suppressed the intracellular ROS levels. After blocking the EMT, administration of GC7 or N-acetyl-L-cysteine did not reduce cell migration further. Based on the experimental data, we concluded that inhibition of eIF5A2 alters progression of the EMT to decrease the invasion and metastasis of HCC cells via ROS-related pathways.

Epidermolytic palmoplantar keratoderma (EPPK) is the most frequent form of such keratodermas. It is inherited in an autosomal dominant pattern and is clinically characterized by diffuse yellowish thickening of the skin on the palms and soles with erythematous borders during the first weeks or months after birth. EPPK is generally caused by mutations of the KRT9 gene. More than 26 KRT9 gene mutations responsible for EPPK have been described (Human Intermediate Filament Database, www.interfil.org), and many of these variants are located within the highly-conserved coil 1A region of the α-helical rod domain of keratin 9. Unfortunately, there is no satisfactory treatment for EPPK. Thus, prenatal molecular diagnosis or pre-pregnancy diagnosis is crucial and benefits those affected who seek healthy descendants. In the present study, we performed amniotic fluid-DNA-based prenatal testing for three at-risk pregnant EPPK women from three unrelated southern Chinese families who carried the KRT9 missense mutations p.Arg163Trp and p.Arg163Gln, and successfully helped two families to bear normal daughters. We suggest that before the successful application of preimplantation genetic diagnosis (PGD), and noninvasive prenatal diagnosis of EPPK that analyzes fetal cells or cell-free DNA in maternal blood, prenatal genetic diagnosis by amniocentesis or chorionic villus sampling (CVS) offers a quite acceptable option for EPPK couples-at-risk to avoid the birth of affected offspring, especially in low- and middle-income countries.

Retinoblastoma (RB) is the most common malignant intraocular tumor in children. Fifty percent of RB patients are carriers of a predisposing germline mutation with high penetrance. RB1 has been identified as the only pathological gene. We present the rapid detection of an RB1 gene mutation in a Han pedigree of two RB patients from southern China. Total RNA was extracted from whole blood for reverse transcriptase–polymerase chain reaction (PCR) to analyze RB1 transcripts, and genomic DNA for PCR and direct sequencing to test RB1 exons. Allele-specific PCR was used to verify the mutation. The results showed that the bilaterally affected son and the unilaterally affected father were both heterozygous for the nonsense mutation c.1363C>T (p.R455X) in exon 14 of RB1. Our studies suggest the molecular basis of RB in this Chinese family and provide further evidence that codon 455 is one of the recurrent spots for mutations in RB1.

Epidermolytic palmoplantar keratoderma (EPPK) is a relatively common autosomal-dominant skin disorder caused by mutations in the keratin 9 gene (KRT9), with few therapeutic options for the affected so far. Here, we report a knock-in transgenic mouse model that carried a small insertion-deletion (indel) mutant of Krt9, c.434delAinsGGCT (p.Tyr144delinsTrpLeu), corresponding to the human mutation KRT9/c.500delAinsGGCT (p.Tyr167delinsTrpLeu), which resulted in a human EPPK-like phenotype in the weight-stress areas of the fore- and hind-paws of both Krt9(+/mut) and Krt9(mut/mut) mice. The phenotype confirmed that EPPK is a dominant-negative condition, such that mice heterozygotic for the K9-mutant allele (Krt9(+/mut)) showed a clear EPPK-like phenotype. Then, we developed a mutant-specific short hairpin RNA (shRNA) therapy for EPPK mice. Mutant-specific shRNAs were systematically identified in vitro using a luciferase reporter gene assay and delivered into Krt9(+/mut) mice. shRNA-mediated knockdown of mutant protein resulted in almost normal morphology and functions of the skin, whereas the same shRNA had a negligible effect in wild-type K9 mice. Our results suggest that EPPK can be treated by gene therapy, and this has significant implications for future clinical application.

Stargardt disease-3 (STGD3) is an autosomal dominant juvenile-onset macular dystrophy characterized by progressive decreasing visual acuity, bilateral atrophic changes in the macula and absence of characteristic dark choroids. We identified a STGD3-like macular dystrophy pedigree by clinical examination. To explore whether the STGD3-like phenotype in the kindred is linked to ELOVL4 gene or associated with any other identified STGD gene, we extracted genomic DNA from leukocytes of peripheral blood from the available family members and 50 normal controls for mutation analysis. Then the exons of ELOVL4, RDS and the three exons of ABCR were amplified by polymerase chain reaction (PCR). All PCR products were screened for mutations by combination of denaturing high-performance liquid chromatography (DHPLC) analysis and DNA sequencing. No mutation was found in the exons of three candidate genes, but we obtained three non-pathogenic polymorphisms, IVS5-2533T-->A in ELOVL4, 558C-->T (Vall06Val) and 1150G-->C (Glu304Gln) in RDS. And IVS5-2533T-->A is never shown in the previous references. These data suggested that there exist other unknown genes responsible for the STGD3-like phenotype in the pedigree.

Ossification of the posterior longitudinal ligament (OPLL) of the cervical spine is a complex multifactorial disease. Patients with OPLL commonly present with symptoms in their 40s or 50s. The genetic basis of OPLL remains poorly understood. Exome capture combined with massively parallel DNA sequencing has been proposed as an efficient strategy to search for disease-causing genes of both monogenic and multigenic disorders. To identify candidate pathogenic genes associated with OPLL, we performed whole exome sequencing (WES) on two unrelated southern Chinese OPLL patients. The entire DNA coding region of the candidate genes was amplified by PCR and Sanger sequenced. The common single nucleotide polymorphisms were analyzed by association studies. WES revealed p.T265S/PTCH1, p.P1232L/PTCH1, and p.T902S/COL17A1 mutants in the two female cases with mixed OPLL. These were confirmed by Sanger sequencing. p.P1232L/PTCH1, p.N1374D/COL17A1 and p.T902S/COL17A1 were subsequently identified in three males with continuous OPLL and one female with mixed OPLL. The association studies indicated that the SNPs rs805698 and rs4918079 in COL17A1 were significantly associated with OPLL. This study suggests that WES may be a practical approach to revealing significant genetic involvement in OPLL. Variants of the PTCH1 and COL17A1 genes may contribute to the development of OPLL.

The great majority of genetic disorders are caused by defects in the nuclear genome. However, some significant diseases are the result of mitochondrial mutations. Because of the unique features of the mitochondria, these diseases display characteristic modes of inheritance and a large degree of phenotypic variability. Recent studies have suggested that mitochondrial dysfunction plays a central role in a wide range of age-related disorders and various forms of cancer.

Purpose To examine the fibrillin-1 ( FBN1 ) gene for mutations in members of a Chinese family with isolated ectopia lentis. Design Clinically relevant laboratory investigation. Methods Family members underwent clinical examinations. Genomic DNA was extracted from leukocytes of peripheral blood from the available members and 100 controls for mutation analysis. The 65 exons of FBN1 were amplified by polymerase chain reaction and screened for mutations by a combination of denaturing high-performance liquid chromatography analysis and direct DNA sequencing. Results A mutation, c.184C→T in exon 2 of FBN1 , which results in substitution of arginine by cysteine at position 62 of the fibrillin-1 protein (p.R62C) in all affected family members but in none of the unaffected individuals. Conclusions A recurrent mutation of FBN1 gene resulted in an arginine-to-cysteine residue (p.R62C), is responsible for the patients with isolated ectopia lentis in a Chinese family.

Serotonin (5-hydroxytryptamine; 5-HT) is a neurotransmitter that occupies a uniquely important place in neurobiology because of its role in many physiologic processes such as sleep, appetite, thermoregulation, pain perception, hormone secretion, and sexual behavior. Serotonin dysfunction has been implicated in the pathogenesis of schizophrenia. Previous studies have shown an association between the T102C polymorphism of the 5-hydroxytryptamine receptor 2A (HTR2A) gene and schizophrenia. However, many negative findings have also been reported. We analyzed the T102C polymorphism of HTR2A of schizophrenic patients in two southern Chinese populations (n = 291) and matched controls (n = 307). No significant positive association was observed between either of the polymorphisms and all schizophrenics, nor was the polymorphisms and any population of schizophrenia. These data did not provide evidence for a contribution of the 102T/C SNP of HTR2A gene to susceptibility to the southern Han Chinese schizophrenia.

Von Hippel-Lindau (VHL) disease is an autosomal dominant familial cancer syndrome. VHL is characterized by the development of renal cell carcinoma (RCC), hemangioblastomas of the central nervous system or retina and pheochromocytoma (PCC). RCC and PCC are known to be caused by germline mutations of six and ten genes, respectively. In the present study, 30 individuals from two unrelated pedigrees with type 2A and 2C VHL syndrome were investigated. The patients were clinically examined and treated by radical nephrectomy [or nephron‑sparing surgery (NSS)] and cortical-sparing adrenalectomy (CSA), and all members of the two families underwent genetic screening. Two members from the first family were diagnosed with PCC and RCC, and three individuals from the second family who had only hypertension were diagnosed with PCC. Heterozygous variants of the VHL gene, c.A233G (p.N78S) within exon 1 and c.G482A (p.R161Q) within exon 3, were verified, respectively. Surgery was performed on all the patients, with the exception of an asymptomatic 5-year-old p.N78S male in family 1, in addition to genetic testing and genetic counseling. Further patient follow-up was warranted with regard to blood pressure and health, although normal blood pressure and no local recurrence and distant metastasis of VHL were observed previously. The present study suggests that molecular genetic testing may aid the diagnosis and clinical management of VHL syndrome.

Introduction: Early and normative surgery is the only curative method for multiple endocrine neoplasia type 2 (MEN 2)-related medullary thyroid carcinoma (MTC). Aims: To study the timing of prophylactic total thyroidectomy (TT) for MEN 2-related MTC with different RET mutations in a Chinese population, and to compare the sensitivity and accuracy of fully-automated chemiluminescence immunoassay (FACLIA) and radioimmunoassay (RIA) for serum calcitonin (Ct). Methods: We collected 24 asymptomatic individuals from 8 unrelated Chinese families with MEN 2, and analyzed RET mutation and Ct levels. Then we performed TT on 17 of the 24 individuals, including TT (2/17), TT with bilateral level VI lymph-node dissection (B-LND(VI); 12/17) and TT with B-LND(VI) þ modified unilateral/bilateral/local neck dissection (3/17). Results: Histopathology revealed bilateral/unilateral MTC in 15/17 (88.2%; median diameter, 1.0 cm) and bilateral C-cell hyperplasia in 2/17 (11.8%; p.V292M/R67H/R982C and p.C618Y). Lymph-node metastasis/fibro-adipose tissue invasion (p.C634R) or solely fibroadipose tissue invasion (p.C634Y) were found in 2/17 (11.8%). Elevated pre-surgical Ct (pre-Ct) was identified by FACLIA in 17/17 (median age, 24.0), while pre-Ct by RIAwas found in only 6/15 (P < 0.001). The median follow-up was 22.0 months, during which 16/17 had no abnormality (one p.C634R individual had elevated Ct), and another 7 carriers still had consistently undetectable Ct by FACLIA. Conclusions: Our study highlights the importance and feasibility of individualized prophylactic TT for MEN 2-related MTC, based on predictive integrated screening of RET and pre-Ct levels. Besides, we recommend FACLIA to measure Ct for earlier diagnosis, treatment and follow-up monitoring of MTC. 2013 Elsevier Ltd. All rights reserved.

Genetic screening for germline mutations in the RET proto-oncogene has been extensively exploited worldwide to optimize the diagnostic and clinical management of multiple endocrine neoplasia type 2 (MEN2) patients and their relatives. However, a distinct lag period exists not only in the recognition but also in the medical treatment of patients with MEN2. Here we present a comprehensive genetic and clinical analysis of MEN2 among Chinese families followed from 1975 to 2011. Our series comprises 36 index cases and 134 relatives from 11 independent families.Genetic diagnosis was performed in all participants by direct sequencing all relevant RET exons. Thyroidectomy was performed in 50 patients with varying cervical neck dissection procedures. Patients with pheochromocytoma (PHEO) underwent specific surgery. Demographic, clinical profiles, mutation types, tumor histopathologic features, and follow-up records were systematically analyzed.The RET mutations p.C634Y (n=34), p.C634R (n=6), p.C618S (n=13), p.V292M/R67H/R982C (n=7), p.L790F (n=2), and p.C634Y/V292M/R67H/R982C (n=1) were confirmed in 31 index cases and then identified in 32 at-risk relatives (mutation carriers), with MEN2A as the most common clinical subtype. The overall penetrance of PHEO in patients with MEN2A was 46.7%. A total of 50 patients underwent thyroidectomy, and there was a significant lowering of their mean age at thyroidectomy and the tumor diameter of the mutation carriers that were detected and operated on compared with the index cases (age at first surgery: 29.3 vs. 39.3 years, p0.05; maximum size: 1.1 vs. 3.3 cm, p0.001). There was also a decrease in the TNM staging and the proportion of patients who underwent inappropriate initial thyroid surgery (pN1: 31.6% vs. 100%, p0.001; inappropriate surgery: 0% vs. 29%). Meanwhile, disease-free survival (DFS) increased (DFS: 100% vs. 58.1%, p0.05). Both medullary thyroid carcinoma-specific (n=1) and PHEO-specific (n=5) deaths were reported during the study period.Our results further substantiate that gene scanning of all relevant RET exons is a powerful tool in the management of MEN2 patients, especially in asymptomatic carriers, and has led to earlier diagnosis and more complete initial treatment of patients with MEN2 in China.

Mutation-based molecular diagnostics of autosomal dominant polycystic kidney disease (ADPKD) is complicated by genetic and allelic heterogeneity, large multi-exon genes, and duplication sequences of PKD1. Recently, targeted resequencing by pooling long-range polymerase chain reaction (LR-PCR) amplicons has been used in the identification of mutations in ADPKD. Despite its high sensitivity, specificity and accuracy, LR-PCR is still complicated. We performed whole-exome sequencing on two unrelated typical Chinese ADPKD probands and evaluated the effectiveness of this approach compared with Sanger sequencing. Meanwhile, we performed targeted gene and next-generation sequencing (targeted DNA-HiSeq) on 8 individuals (1 patient from one family, 5 patients and 2 normal individuals from another family). Both whole-exome sequencing and targeted DNA-HiSeq confirmed c.11364delC (p.H3788QfsX37) within the unduplicated region of PKD1 in one proband; in the other family, targeted DNA-HiSeq identified a small insertion, c.401_402insG (p.V134VfsX79), in PKD2. These methods do not overcome the screening complexity of homology. However, the true positives of variants confirmed by targeted gene and next-generation sequencing were 69.4%, 50% and 100% without a false positive in the whole coding region and the duplicated and unduplicated regions, which indicated that the screening accuracy of PKD1 and PKD2 can be largely improved by using a greater sequencing depth and elaborate design of the capture probe.

Mutations in the KRT6A or KRT16 gene cause pachyonychia congenita type 1 (PC-1), while mutations in KRT16 or KRT6C underlie focal palmoplantar keratoderma (FPPK). A new classification system of PC has been adopted based on the mutated gene. PC rarely presents the symptoms of diffuse plantar keratoderma. Mutation in the tail domain of keratins is rarely reported. PC combined with fissured tongue has never been described. To investigate the genotype-phenotype correlations between clinical features and gene mutational sites in two unrelated southern Chinese PC pedigrees (one family presented with specific fissured tongue, the other with diffuse plantar keratoderma). The whole coding regions of the KRT6A/KRT16/KRT17/KRT6B genes were amplified and directly sequenced to detect the mutation. To confirm the effect of the IVS8-2A>C mutation in KRT6A at the mRNA level, total RNA from the plantar lesion of a patient was extracted and reverse-transcribed to cDNA for sequence analysis. Two novel de novo mutations, a splice acceptor site variant IVS8-2A>C (p.S487FfsX72) in KRT6A and a heterozygous substitution c.AA373_374GG (p.N125G) within exon 1 of KRT16, were found separately in the two PC families. Genotype-phenotype correlations among PC patients with codon-125 mutation in KRT16 were established, while the phenotypes caused by the IVS8-2A>C mutation in KRT6A need further studies to confirm the rare feature of fissured tongue.

Danon disease is a rare X-linked lysosomal storage disease characterized by hypertrophic cardiomyopathy, myopathy and mental retardation, and is due to a primary defect in lysosome-associated membrane protein-2 (LAMP 2). More than 26 mutations in the LAMP2 gene have been described, including a small number of de novo mutations, some of which are suspected to be caused by germline mosaicism. Here, we describe the first molecularly documented evidence of somatic mosaicism for a LAMP2 mutation, identified in the asymptomatic mother of a boy with Danon disease caused by the frameshift mutation c.808dupG (p.A270Gfx3) within exon 6. In addition, in order to gain insight into the possible explanation for the mother's lack of phenotype, the level of somatic mosaicism and the X-chromosome inactivation pattern were investigated. This study provides new insight into the causes of phenotypic variability in female mutation-carriers and underlines the importance of parental molecular testing for accurate genetic counseling for Danon disease.

We report a Chinese pedigree with familial medullary thyroid carcinoma. Direct sequencing of the entire coding sequences of Rearranged during Transfection (RET) identified a recurrent c.T1852A (p.C618S) mutation in 13 of 23 members. The polymorphisms c.A135G (p.A45A), c.A1296G (p.A432A), c.T2307G (p.L769L) and IVS19 + 15T > C were also found in 13 carriers, and c.G2073A (p.G691S) was found in 1 carrier. Of the 13 carriers, seven (mean age: 42.6 years, range: 27-64) presented MTC as the isolated clinical phenotype, with elevated basal serum calcitonin (average: 1077.9 ng/L, range: 504-2,652) and a mean diameter of thyroid nodules of 2.97 cm (range: 1.6-4.3); they underwent a total thyroidectomy with modified bilateral/unilateral neck dissection and/or level VI lymph node dissection. The other 6 carriers did not accept surgery (4 rejected, 2 awaited). These were 2 older patients (63 and 32 years) with elevated calcitonin (1359 and 41.4 ng/L) and multi-centric hypoechoic nodules (1.5 and 0.6 cm) with calcifications in both/left thyroid lobes; and Doppler ultrasound showed normal bilateral thyroids in 4 younger carriers (median age: 8.3 years, range: 4-12) but with increased calcitonin (average: 9.7 ng/L, range: 7.87-12.2) in 3 of them. The phenotype here is consistent with the clinical symptoms reported worldwide. We recommend that screening of hotspot regions of RET should be preferentially carried out, while whole-exon sequencing should be performed when clinical signs fail to reveal hotspot mutations or different phenotype discrepancies. Moreover, we strongly suggest prophylactic thyroidectomy should be performed before age 5 in carriers with p.C618S to prevent the occurrence and metastasis of MTC.

Knuckle pads and camptodactyly are overlapping symptoms associated with many genetic and environmental factors. To the best of our knowledge, all reported cases of epidermolytic palmoplantar keratoderma (EPPK) with knuckle pads have been without accompanying camptodactyly. We here report a novel KRT9 mutation-EPPK family with combined knuckle pads and camptodactyly. All the EPPK-affected individuals in this southern Chinese pedigree suffered severe diffuse palmar and plantar hyperkeratosis including hyperhidrosis and cuticle splitting: 3 females presented EPPK only, 8 adult males had notably severe knuckle pads and camptodactyly as well as EPPK, and one 6-year-old boy manifested EPPK with knuckle pads. Haplotype analysis excluded the known candidate loci for camptodactyly and/or knuckle pad-like phenotypes on chromosomes 13q12, 3q11.2-q13.12, 1q24-q25, 4p16.3 and 16q11.1-q22, while only the markers D17S1787 and D17S579 flanking KRT9 showed co-segregation with EPPK. Then a novel c.T1373C (p.L458P) mutation within the sixth exon of KRT9 was validated, and this mutation presented a more severe pathogenicity than the previously reported p.L458F. We speculated that KRT9 plays a complicated role in the genesis of EPPK with knuckle pads and camptodactyly, which needs to be further investigated.

BackgroundWhole exome sequencing provides a labor-saving and direct means of genetic diagnosis of hereditary disorders in which the pathogenic gene harbors a large cohort of exons. We set out to demonstrate a suitable example of genetic diagnosis of MEN 2A/FMTC (multiple endocrine neoplasia type 2/familial medullary thyroid carcinoma) using this approach.Methodology/principal findingsWe sequenced the whole exome of six individuals from a large Chinese MEN2A/FMTC pedigree to identify the variants of the RET (REarranged during Transfection) protooncogene and followed this by validation. Then prophylactic or surgical thyroidectomy with modified or level VI lymph node dissection and adrenalectomy were performed for the carriers. The cases were closely followed up. Massively parallel sequencing revealed four missense mutations of RET. We unexpectedly discovered that the proband's daughter with MEN 2A-related MTC presented a novel p.C634Y/V292M/R67H/R982C compound mutation, due to the involvement of p.C634Y in the proband with MEN 2A and p.V292M/R67H/R982C in the proband's husband with FMTC. In the maternal origin, p.C634Y caused bilateral MTC in all 5 cases and bilateral pheochromocytoma in 2 of the 5; the earliest onset age was 28 years. In the paternal origin, one of the six p.V292M/R67H/R982C carriers presented bilateral MTC (70 years old), one only had bilateral C-cell hyperplasia (44 years), two had bilateral multi-nodules (46 and 48 years) and two showed no abnormality (22 and 19 years).Conclusions/significanceThe results confirmed the successful clinical utility of whole exome sequencing, and our data suggested that the p.C634Y/V292M/R67H/R982C mutation of RET exhibited a more aggressive clinical phenotype than p.C634Y or p.V292M/R67H/R982C, while p.V292M/R67H/R982C presented a relatively milder pathogenicity of MTC and likely predisposed to FMTC.

Spinal muscular atrophy (SMA) is a disorder characterized by degeneration of lower motor neurons and occasionally bulbar motor neurons leading to progressive limb and trunk paralysis as well as muscular atrophy. Three types of SMA are recognized depending on the age of onset, the maximum muscular activity achieved, and survivorship: SMA1, SMA2, and SMA3. The survival of motor neuron (SMN) gene has been identified as an SMA determining gene, whereas the neuronal apoptosis inhibitory protein (NAIP) gene is considered to be a modifying factor of the severity of SMA. The main objective of this study was to analyze the deletion of SMN1 and NAIP genes in southern Chinese children with SMA. Here, polymerase chain reaction (PCR) combined with restriction fragment length polymorphism (RFLP) was performed to detect the deletion of both exon 7 and exon 8 of SMN1 and exon 5 of NAIP in 62 southern Chinese children with strongly suspected clinical symptoms of SMA. All the 32 SMA1 patients and 76% (13/17) of SMA2 patients showed homozygous deletions for exon 7 and exon 8, and all the 13 SMA3 patients showed single deletion of SMN1 exon 7 along with 24% (4/17) of SMA2 patients. Eleven out of 32 (34%) SMA1 patients showed NAIP deletion, and none of SMA2 and SMA3 patients was found to have NAIP deletion. The findings of homozygous deletions of exon 7 and/or exon 8 of SMN1 gene confirmed the diagnosis of SMA, and suggested that the deletion of SMN1 exon 7 is a major cause of SMA in southern Chinese children, and that the NAIP gene may be a modifying factor for disease severity of SMA1. The molecular diagnosis system based on PCR-RFLP analysis can conveniently be applied in the clinical testing, genetic counseling, prenatal diagnosis and preimplantation genetic diagnosis of SMA.

Schizophrenia is a common disease with complex mode of inheritance; great efforts have been made to identify the susceptible genes. Catechol-O-methyltransferase (COMT) gene has long been considered as a candidate gene mainly because of two reasons: First, it encodes a key dopamine catabolic enzyme. Second, it maps to the velocardiofacial syndrome (VCFS) region of chromosome 22q11, which is associated with schizophrenia predisposition. Numerous case-control and family-based studies have been conducted, majority of them focused on a functional Val/Met polymorphism (rs4680). Unfortunately, these studies have produced conflicting results. In a previous report, Shifman et al. found a three-marker haplotype (rs737865-rs4680-rs165599) that showed significant association with schizophrenia. In this study, we try to replicate their findings in Chinese Han population and failed to find any associations.

Auteur(s) : Chen-Ming Xu1,2, Xiao-Ling Chen2, Chun-Yue Chen2, Xian-Ning Zhang2 1Department of Reproductive Endocrinology, Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, China 2Institute of Cell Biology and Department of Biochemistry & Genetics, National Education Base for Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou, China Epidermolytic palmoplantar keratoderma (EPPK, OMIM: 144200) is an autosomal dominant [...]