Two novel missense mutations in HAIRY-AND-ENHANCER-OF-SPLIT-7 in a family with spondylocostal dysostosis

Spondylocostal dysostosis (SCD) is an inherited disorder with abnormal vertebral segmentation that results in extensive hemivertebrae, truncal shortening and abnormally aligned ribs. It arises during embryonic development by a disruption of formation of somites (the precursor tissue of the vertebrae, ribs and associated tendons and muscles). Four genes causing a subset of autosomal recessive forms of this disease have been identified: DLL3 (SCDO1: MIM 277300), MESP2 (SCDO2: MIM 608681), LFNG (SCDO3: MIM609813) and HES7 (SCDO4). These genes are all essential components of the Notch signalling pathway, which has multiple roles in development and disease. Previously, only a single SCD-causative missense mutation was described in HES7. In this study, we have identified two new missense mutations in the HES7 gene in a single family, with only individuals carrying both mutant alleles being affected by SCD. In vitro functional analysis revealed that one of the mutant HES7 proteins was unable to repress gene expression by DNA binding or protein heterodimerization.     

A cluster of autosomal recessive spondylocostal dysostosis caused by three newly identified DLL3 mutations segregating in a small village

In 1982, one of us reported a cluster of eight individuals affected by spondylocostal dysostosis (SD, MIM 277300) in four nuclear families indigenous to a village from eastern Switzerland. We tested the hypothesis that the molecular basis for this cluster was segregation of a single mutation in the DLL3 gene, recently linked to SD. Marker haplotypes around the DLL3 locus contradicted this hypothesis as three different haplotypes were seen in affected individuals, but sequence analysis showed that three unreported DLL3 mutations were segregating: a duplication of 17 bp in exon 8 (c.1285-1301dup), a single-nucleotide deletion in exon 5 (c.615delC), and a R238X nonsense mutation in exon 6. Contrary to our initial assumption of a single allele segregating in this small community, three different pathogenic alleles were observed, with a putative founder mutation occurring at the homozygous state but also compounding with, and thus revealing, two other independent mutations. As all three mutations predict truncation of the DLL3 protein and loss of the membrane-attaching domain, the results confirm that autosomal recessive spondylocostal dysostosis represents the null phenotype of DLL3, with remarkable phenotypic consistency across families.     

Lung resection for primary bronchial carcinoma in a patient with complete situs inversus

Complete situs inversus is a rare syndrome with a frequency estimated at 1-2/10,000 births. Situs inversus may go unrecognized until discovery during emergency surgery or investigation of symptoms. We present a case of confirmed adenocarcinoma of the left lung, treated by upper lobectomy. The computed tomography (CT) scan of the thorax showed a mirror-image of the organs and vessels, confirmed by aortography and pneumoangiography. The heart was structurally normal. Abdominal CT scan showed a mirror-image of the abdominal organs. At thoracotomy, the gross appearance of the left lung and the arrangement of the pulmonary vessels and the bronchi corresponded to that normally found on the right side. Preoperative diagnosis of situs inversus in patients undergoing surgical treatment is important for operative technique and prevention of vessel injury. Preoperative angiographic examination is mandatory in patients with situs inversus undergoing lung resection.     

Anomalies of lateralization in man a case of total situs inversus

Total or complete visceral situs inversus is the complete inversion of position of the thoracic and abdominal viscera. The aim of this study is to report a case of complete situs inversus and to review our knowledge of the anomalies of lateralization. A case of complete sinus inversus was discovered incidentally during anatomic dissection in a female subject aged 87 years. The thoracic and abdominal organs had a position symmetric with the normal. This was associated with a common mesentery and incomplete rotation of the colon, placing the cecum under the left lobe of the liver. These alimentary anomalies were discovered in adult life during a surgical operation for small intestinal occlusion, as evidenced by the abdominal scar and peritoneal adhesions. No cardiac, pulmonary, splenic or facial sinus anomalies were encountered. The incidence of complete situs inversus is estimated as 1/8000 in the general population. It may be isolated or associated with malformations, especially cardiac or alimentary. It may be discovered in infancy because of associated anomalies but often remains asymptomatic and discovered by chance in adult life. Complete situs inversus may form part of the multiple malformational syndromes such as that of Kartagener, with recessive autosomal transmission (complete situs inversus, bronchiectasis, chronic sinusitis, male infertility), which represents 20–25% of cases of complete situs inversus. In view of the frequency of this type of anomaly, a knowledge of anomalies of lateralization is essential in clinical practice.     

Agnathia,holoprosencephaly, and situs inversus. Report of a case

We present the first documented case of agnathia-holoprosencephaly (an uncommon form of craniofacial anomaly) associated with situs inversus. This case may represent the concordance of multiple field complex anomalies, but the possibility of a major midline malformation (situs inversus) caused by a timed insult (environmental or genetic) which affects multiple structures and occurs concurrently with a major field defect during early embryogenesis cannot be excluded.     

Novel homozygous variant in ARL2BP associated with retinitis pigmentosa,situs inversus,and male infertility in a Chinese patient

ARL2BP is a ciliary gene associated with multiple ciliopathy phenotypes. On comprehensive clinical examinations using molecular methods, we identified a Chinese patient from a consanguineous family carrying a novel homozygous variant c.22_23delAG (p.S8Lfs*10) in ARL2BP, presenting with retinitis pigmentosa (RP), situs inversus totalis, and oligozoospermia. Situs inversus and male infertility have never been reported in the same patient with ARL2BP variants; therefore, this a novel ARL2BP-associated phenotypic triad of RP, situs inversus, and male infertility. Moreover, this patient likely had olfactory dysfunction susceptibility and presented with anosmia. We found reduced patient-derived fibroblast proliferation and ciliary length. Our findings expand the genotypic spectrum and reveal abnormal cell proliferation and ciliogenesis in ARL2BP-associated patients.     

Identification of bi-allelic LFNG variants in three patients and further clinical and molecular refinement of spondylocostal dysostosis 3

Spondylocostal dysostosis (SCD), a condition characterized by multiple segmentation defects of the vertebrae and rib malformations, is caused by bi-allelic variants in one of the genes involved in the Notch signaling pathway that tunes the “segmentation clock” of somitogenesis: DLL3, HES7, LFNG, MESP2, RIPPLY2, and TBX6. To date, seven individuals with LFNG variants have been reported in the literature. In this study we describe two newborns and one fetus with SCD, who were found by trio-based exome sequencing (trio-ES) to carry homozygous (c.822-5C>T) or compound heterozygous (c.[863dup];[1063G>A]) and (c.[521G>T];[890T>G]) variants in LFNG. Notably, the c.822-5C>T change, affecting the polypyrimidine tract of intron 5, is the first non-coding variant reported in LFNG. This study further refines the clinical and molecular features of spondylocostal dysostosis 3 and adds to the numerous investigations supporting the usefulness of trio-ES approach in prenatal and neonatal settings.     

Unusual occurrence of dextrocardia with situs inversus in succeeding generations of a family.

In three cases of dextrocardia with situs inversus affecting a father and his two sons, the father had married his first cousin, the daughter of his father's sister, so that the two sons were the products of a consanguineous marriage. The general and familial incidence of the condition and the genetic influences responsible for it are discussed.     

X-linked laterality sequence in a family with carrier manifestations

X-linked laterality sequence (XLLS) consists of situs inversus, complex cardiac defects, and alterations in the development of the spleen. We describe a family in which two male cousins had XLLS with caudal manifestations. In our family, the obligate carrier females had uterine septum and hypertelorism, which may be gene carrier manifestations. © 1994 Wiley-Liss, Inc.     

颅面畸形家系的胎儿产前诊断与分析

目的 探讨先天性颅面畸形胎儿的产前诊断技术.方法 选择产前检查B超显示胎儿具有颅面畸形的孕妇1例,采集孕妇羊水、外周血和其丈夫外周血样本,进行常规G显带核型分析.再采用比较基因组杂交技术(aaray comparative genomic hybridization,array-CGH)进行全基因组高分辨扫描和分析,逆转录荧光定量PCR方法对array-CGH结果进行验证.并在患儿出生后再进行重复检测确认.结果 G显带核型分析未见异常,array-CGH显示胎儿1p36.33区域有重复,长度约为722 kb,该片段中VWA1和PYGO2基因与软骨发育有关,定量PCR实验证实了比较基因组杂交的结果,拟诊为颅面畸形,胎儿出生后得到进一步确认.结论 应用比较基因组杂交技术,成功对1例先天性颅面畸形胎儿进行了产前诊断,并确定了两个与颅面骨发育有关的候选基因VWA1和PYGO2.     

Syndromal frontonasal dysostosis in a child with a complex translocation involving chromosomes 3, 7, and 11

We report on a 4-year-old boy with typical frontonasal dysostosis and an apparently balanced de novo translocation involving chromosomes 3, 7, and 11, and four breakpoints. The karyotype was 46,XY,t(7;3)(3;11) (7pter→7q21.3::3q27→3qter;3pter→3q23::11q21→11qter;11pter→11q21::3q23→3q27::7q21.3→7qter). In situ hybridization with a chromosome 3 painting probe confirmed the interpretation from GTG banding. The child had a widow's peak, marked hypertelorism, absence of the nasal tip, and widely separated nares. He also had an atrial septal defect, micropenis, small testes, clubfeet, scoliosis, block C2–4, and structural brain abnormalities on MRI. In review we found two other cases of frontonasal dysostosis with chromosome abnormalities, neither of which was similar to our case. The presence of a denovo (apparently) balanced translocation in our patient may help to locate the gene(s) for frontonasal dysplasia and perhaps other midline craniofacial malformations. © 1995 Wiley-Liss, Inc.     

Syndrome of acrofacial dysostosis,cleft lip/palate,and triphalangeal thumb in a brazilian family

We describe two daughters of a nonconsanguineous couple. Both had facial and skeletal anomalies, but in quantitatively and qualitatively different ways. In one patient signs of mandibulofacial dysostosis are associated with anomalies of the radial rays of both arms. In the other, cleft lip and cleft palate are associated with hypoplastic thumbs. Clinical and genetical aspects of present case are discussed.     

小睑裂综合征家系的FOXL2基因突变研究

目的 对小睑裂综合征家系患者的FOXL2基因突变进行研究，寻找突变位点。方法 设计FOXL2基因特异性引物进行PCR扩增，然后测序，并对突变位点进行克隆后测序。结果 在一个类型尚不明确的家系中2例患者FOXL2基因PCR扩增后测序发现951—953（delc），克隆后多克隆位点测序亦证实951—953（delC）。所有正常人均未发现突变。951—953（delC）引起238位S后出现移码突变，终止密码子提前，蛋白截短。结论 951－953（delC）致蛋白截短，可能是导致小睑裂综合征的原因。经查新验证．951－953（delC）是一个新的突变位点，国内外未见报道。     

Trinucleotide expansions in the SCA7 gene in a large family with spinocerebellar ataxia and craniocervical dystonia

Spinocerebellar ataxia type 7 is a rare autosomal dominant cerebellar ataxia (ADCA). Herein, we describe the molecular and clinical findings in patients within six generations of a large Chinese family with spinocerebellar ataxia. To identify the genetic cause(s), 4 affected patients and 26 asymptomatic relatives were recruited for the study. Molecular screening of the SCA1 and SCA7 genes was carried out by subcloning and direct PCR-sequencing methods. Both neurological and ophthalmic examinations were performed to investigate the clinical characteristics of the disease. The patients had typical cerebellar ataxia, achromatopsia and macular degeneration, and displayed a rare phenotype manifesting as a combination of cerebellar ataxia and craniocervical dystonia. Mutational analysis of the SCA7 genes demonstrated expanded CAG-repeats in the four patients. In conclusion, we identified expanded CAG-repeats in the SCA7 gene within members of a large Chinese family with spinocerebellar ataxia. The defined phenotypic characteristics of the patients may be helpful for clinical diagnosis and genetic typing of new patients.     

Analysis of FOXL2 gene mutation and genotype-phenotype correlation in a Chinese pedigree affected with blepharophimosis-ptosis-epicanthus inversus syndromeCSCD

Objective: To detect FOXL2 gene mutation in a Chinese pedigree affected with blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) type I, and to explore its genotype - phenotype correlation. Methods: Peripheral blood samples were obtained from 3 patients and 19 healthy members from the pedigree for the isolation of genomic DNA. All exons and flanking sequences of the FOXL2 gene were amplified by PCR with 7 pairs of overlapping primers and sequenced. Results DNA sequencing indicated that the BPES phenotype in this pedigree was caused by a hotspot c. 843-859dupl7 mutation. The same mutation was not found among the healthy members of the pedigree. Conclusion: The c. 843-859dupl7 frameshift mutation probably underlies the BPES type I in this Chinese pedigree, which may manifest as either BEPS type I or type II. © 2018 MeDitorial Ltd. All rights reserved.     

Evaluation of 64 candidate single nucleotide polymorphisms as risk factors for neural tube defects in a large Irish study population

Individual studies of the genetics of neural tube defects (NTDs) contain results on a small number of genes in each report. To identify genetic risk factors for NTDs, we evaluated potentially functional single nucleotide polymorphisms (SNPs) that are biologically plausible risk factors for NTDs but that have never been investigated for an association with NTDs, examined SNPs that previously showed no association with NTDs in published studies, and tried to confirm previously reported associations in folate‐related and non‐folate‐related genes. We investigated 64 SNPs in 34 genes for association with spina bifida in up to 558 case families (520 cases, 507 mothers, 457 fathers) and 994 controls in Ireland. Case‐control and mother‐control comparisons of genotype frequencies, tests of transmission disequilibrium, and log‐linear regression models were used to calculate effect estimates. Spina bifida was associated with over‐transmission of the LEPR (leptin receptor) rs1805134 minor C allele [genotype relative risk (GRR): 1.5; 95% confidence interval (CI): 1.0–2.1; P = 0.0264] and the COMT (catechol‐O‐methyltransferase) rs737865 major T allele (GRR: 1.4; 95% CI: 1.1–2.0; P = 0.0206). After correcting for multiple comparisons, these individual test P‐values exceeded 0.05. Consistent with previous reports, spina bifida was associated with MTHFR 677C>T, T (Brachyury) rs3127334, LEPR K109R, and PDGFRA promoter haplotype combinations. The associations between LEPR SNPs and spina bifida suggest a possible mechanism for the finding that obesity is a NTD risk factor. The association between a variant in COMT and spina bifida implicates methylation and epigenetics in NTDs. © 2010 Wiley‐Liss, Inc.     

nNOS和iNOS在神经管畸形胎鼠大脑皮质中的表达及意义

目的 研究乙烯硫脲（ETU）致神经管畸形胎鼠大脑皮质中nNOS和iNOS表达情况,进一步探讨nNOS和iNOS在脑发育中的作用。方法 应用免疫荧光、Western—blot及Real—time PCR方法检测nNOS和iNOS在正常胎鼠、ETU致畸的神经管畸形胎鼠的大脑皮质表达情况并进行定位、定量分析。结果 nNOS在给药无畸形组、脊柱裂畸形组胎鼠大脑皮质中的表达与正常对照组相比无明显差异（p〉0．05）,而在脑膜膨出组胎鼠大脑皮质中nNOS的表达与正常对照组明显减少（p〈0．01）;iNOS在各组均未检测到。结论 nNOS在脑膨出的胎鼠大脑皮质中表达明显减少,提示nNOS参与了脑异常发育过程。     

Asplenia syndrome in a child with a balanced reciprocal translocation of chromosomes 11 and 20 [46,XX,t(11;20)(q13.1;q13.13)]

We present a 6-year-old girl with a balanced 11;20 translocation [46,XX,t(11;20)(q13.1;q13.13)pat], asplenia, pulmonic stenosis, Hirschsprung disease, minor anomalies, and mental retardation. This case represents the second report of an individual with situs abnormalities and a balanced chromosome rearrangement involving a breakpoint at 11q13. Polymerase chain reaction (PCR) analysis of microsatellite markers excluded uniparental disomy for chromosomes 11 and 20. Segregation analysis of markers in the 11q13 region in the proposita and her phenotypically normal carrier sibs did not show a unique combination of maternal and paternal alleles in the patient. We discuss several possible explanations for the simultaneous occurrence of situs abnormalities and a balanced 11;20 translocation. These include (1) chance, (2) a further chromosome rearrangement in the patient, (3) gene disruption and random situs determination, and (4) gene disruption plus transmission of a recessive or imprinted allele from the mother. © 1996 Wiley-Liss, Inc.     

Increased levels of apo-transcobalamins I and II in amniotic fluid from pregnant women with previous neural tube defect offspring

In an attempt to identify biochemical components of the genetic predisposition to neural tube defects (NTDs), levels of folate, cobalamin, apo-transcobalamins I and II and alpha-fetoprotein were studied in midtrimester amniotic fluid from 24 pregnant women who had previously had a child with NTD. The control group consisted of 76 mothers, subjected to amniocentesis for reasons other than risk of NTD in offspring. Only pregnancies with normal outcome were included. No differences were found between groups for levels of folate, cobalamin or alpha-fetoprotein. Folate intake or metabolism did not appear to differ between groups. In contrast, the level of apo-transcobalamin I was doubled and the level of apo-transcobalamin II tripled in amniotic fluid from women who had had a child with NTD compared with the control group. Since the variation in apo-transcobalamin II in adults is to a high degree genetically determined, the present results may suggest that the genetic predisposition to NTD is associated with variation in this protein. Further studies are needed to substantiate or reject this possibility.