Genetic and clinical analysis of a novel GLB1 gene variant in a Chinese patient with GM1-gangliosidosis / 中华医学遗传学杂志

OBJECTIVE@#To explore the genotype-phenotype correlation of a case with GM1-gangliosidosis caused by compound heterogenic variants in GLB1.@*METHODS@#Genomic DNA was extracted from peripheral blood samples from the patient and her parents. Trio-based whole-exome sequencing (WES) was performed for the family and suspected mutation was verified by Sanger sequencing.@*RESULTS@#The proband, a 2-year-3-month old Chinese girl, presented with psychomotor deterioration, absent speech, intellectual disabilities and behavior problem. Trio-based WES has identified compound heterozygosity for 2 variants in the GLB1 gene: NM_000404.2:c.1343A>T, p.Asp448Val and c.1064A>C, p.Gln355Pro (GRCh37/hg19),which was inherited from the mother and father, respectively. Homozygous or compound heterozygous pathogenic variants in GLB1, encoding β-galactosidase, are responsible for GM1-gangliosidosis,an autosomal recessive lysosomal storage disorder characterized by variable degrees of neurodegeneration and skeletal abnormalities. The p.Asp448Val variant has been classified as pathogenic for GM1 gangliosidosis in medical literatures for the reason that functional studies demonstrated that expression of the p.Asp448Val variant in COS-1 cells resulted in no detectable β-galactosidase activity compared to wild type GLB1. The p.Gln355Pro variant has not been reported in literatures or database. The variant is highly conserved residue (PM1), and was not found in either the Genome Aggregation Database or the 1000 Genomes Project (PM2) and was predicted to have a deleterious effect on the gene product by multiple in silico prediction tools (PP3). Next, the β-galactosidase activity of the patient's peripheral blood leukocytes was determined by fluorescent method. The result was 0.0 nmol/mg. It showed that the p.Gln355Pro variant also resulted in loss of β-galactosidase activity, thus the variant was classified into clinical pathogenic variant.@*CONCLUSION@#Our study expands the mutational spectrum of the GLB1 gene and provides genetic counseling for the family.

Genetic and clinical analysis of KIF2A gene variant in a Chinese patient with complex cortical dysplasia and other brain malformations / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child featuring complex cortical dysplasia and other brain malformations (CDCBM3).@*METHODS@#Genomic DNA was extracted from peripheral blood samples from the patient and his parents. Whole exome sequencing (WES) was carried out for the family trio. Suspected variant was verified by Sanger sequencing.@*RESULTS@#The proband, a 1-year-and-2-month old Chinese boy, had presented with motor developmental delay, lissencephaly, severe cognitive impairments, absent speech and congenital laryngomalacia. WES revealed that he has harbored a heterozygous missense variant of the KIF2A gene, namely NM_001098511.2: c.952G>A, p.Gly318Arg (GRCh37/hg19). The highly conserved residue is located around the ATP nucleotide-binding pocket in the kinesin motor domain (PM1). The variant was not found in the Genome Aggregation Database and the 1000 Genomes Project (PM2), and was predicted to be deleterious on the gene product by multiple in silico prediction tools (PP3). This variant was unreported previously and was de novo in origin (PS2). Based on the ACMG guidelines, it was categorized as likely pathogenic (PS2+PM1+PM2+PP3). Furthermore, the congenital laryngomalacia found in our patient was absent in previously reported CDCBM3 cases.@*CONCLUSION@#The novel variant of the KIF2A gene probably underlay the disorders in the proband. Above finding has expanded the phenotypic and mutational spectrum of CDCBM3.

Analysis of OCRL gene variant in a Chinese pedigree affected with Lowe syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genotype-phenotype correlation of a Chinese pedigree affected with Lowe syndrome.@*METHODS@#Whole exome sequencing (WES) and Sanger sequencing were carried out for the proband and members of his pedigree.@*RESULTS@#The proband, a 3-year-and-5-month-old male, presented with multiple anomalies including congenital cataract, glaucoma, brain dysplasia, renal dysfunction and cognitive impairment. WES revealed that he has harbored a novel hemizygous missense variant of the OCRL gene, namely NM_000276.3: c.1255T>C (p.Trp419Arg) (GRCh37/hg19), which was derived from his unaffected mother. The same variant was not found in his elder brother who was healthy. The variant was predicted to be pathogenic according to ACMG/AMP guideline. Compared with previously reported cases of Lowe syndrome, our patient has displayed rare features including corpus callosum dysplasia, reduction of white matter, cerebral hypoplasia, laryngomalacia, sebaceous cyst, recurrent eczema, cryptorchidism, hypoglycemia and irritability.@*CONCLUSION@#Above finding has expanded the mutational spectrum of the OCRL gene, enriched clinical features of Lowe syndrome, and enabled genetic counseling for this pedigree.

Analysis of RUNX2 gene variant in a Chinese patient with cleidocranial dysplasia / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese patient featuring cleidocranial dysplasia(CCD).@*METHODS@#Genomic DNA was extracted from peripheral blood samples of the patient and his parents. Whole exome sequencing (WES) was carried out for the patient, and suspected variant was verified by Sanger sequencing.@*RESULTS@#WES has identified a missense c.460G>T (p.Val154Phe) (GRCh37/hg19) variant of the RUNX2 gene. The variant was located in the Runt domain, a highly conserved region (PM1); it was not present in either the Genome Aggregation Database or the 1000 Genomes Project (PM2), and was predicted to have a deleterious effect on the gene product by multiple in silico prediction tools (PP3); the clinical phenotype of the patient was highly consistent with that of cleidocranial dysplasia (PP4). Furthermore, the variant was unreported in medical literature and was absent in both parents (PS2). Based on the American College of Medical Genetics and Genomics guidelines, the c.460 G>T variant of RUNX2 gene was predicted to be pathogenic (PS2+PM1+PM2+PP3+PP4).@*CONCLUSION@#The c.460G>T (p.Val154Phe) variant of the RUNX2 gene probably underlay the clinical phenotype in the patient. Above finding has enabled accurate diagnosis and expanded the spectrum of RUNX2 variants.

Clinical and genetic analysis of a novel CHD4 gene variant in a Chinese patient with Sifrim-Hitz-Weiss syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genotype-phenotype correlation of a case with Sifrim-Hitz-Weiss syndrome (SIHIWES) caused by a novel CHD4 gene variant.@*METHODS@#Genomic DNA was extracted from peripheral blood samples of the patient and her parents. Whole-exome sequencing (WES) was carried out for the patient.Suspected variant was verified by Sanger sequencing.@*RESULTS@#The proband, a 2-year-old Chinese girl, presented with global developmental delay, intellectual disability, distinctive facial features and multiple congenital anomalies. Her prenatal manifestations included increased nuchal thickness, cranial and facial anomalies, and decreased fetal movement. WES has identified a novel variant in the CHD4 gene, namely NM_001273:c.2989C>G (p.Leu997Val) (GRCh37/hg19).Comparison of her phenotype with previously reported SIHIWES cases suggested that our patient's prenatal presentations were unreported before, with novel features including funduscopic anomaly, facial dysmorphisms such as asymmetrical ears, drooping eyelid, long philtrum and downturned mouth.@*CONCLUSION@#Above findings have expanded the mutational spectrum of the CHD4 gene and revealed novel phenotypes in Chinese patients with SIHIWES.

Analysis of clinical manifestation and a mosaic frameshift variant of the KMT2D gene in a Chinese patient with Kabuki syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genotype-phenotype correlation in a child with Kabuki syndrome type 1 (KS1) caused by a mosaic frameshift variant of KMT2D gene.@*METHODS@#Trio-based whole exome sequencing (WES) was carried for the patient and her parents. Candidate variant was verified by Sanger sequencing.@*RESULTS@#The proband, a 3-year-and-2-month-old Chinese girl, presented with distinctive facial features, cognitive impairment, mild developmental delay, dermatoglyphic abnormalities, minor skeletal anomalies, ventricular septal defect, and autistic behavior. Trio-based WES revealed that the proband has carried a de novo mosaic frameshit variant of the KMT2D gene, namely NM_003482.3:c.13058delG (p.Pro4353Argfs*31) (GRCh37/hg19), for which the mosaicism rate was close to 21%. The variant was unreported previously and was confirmed by Sanger sequencing. Chromosomal microarray analysis (CMA) has revealed no pathogenic or likely pathogenic copy number variations. Compared with previously reported cases, our patient has presented obvious behavior anomalies including autism, anxiety and sleep problems, which were rarely reported.@*CONCLUSION@#This study has expanded the spectrum of KMT2D gene variants, enriched the clinical phenotypes of KS1, and facilitated genetic counseling for the family.

Identification of a 17q25.3 duplication in a Chinese patient with global developmental delay and multiple congenital anomalies / 中华医学遗传学杂志

Objective@#To delineate the clinical features, inheritance pattern, and genotype-phenotype correlation of a Chinese patient with a 17q25.3 duplication.@*Methods@#Whole exome sequencing(WES), chromosomal microarray analysis (CMA), chromosomal karyotyping and fluorescence in situ hybridization(FISH) were employed for the analysis of the proband and his family members.@*Results@#A 5.7 Mb duplication at 17q25.3→qter was identified by WES and CMA in the 4-year-old boy with multiple congenital anomalies, which was classified as a clinically pathogenic variant. This duplication was confirmed by FISH, and was inherited from his unaffected mother who carried a balanced translocation. Further study revealed that his grandmother also carried the balanced translocation but had gestated three healthy children and had no abortion history. His uncle also carried the balanced translocation, while his aunt was normal.@*Conclusion@#Above results have enriched the clinical phenotypes of 17q25.3 duplication. Genetic counseling was provided for the family.P4HB, ACTG1, BAIAP2 and TBCD genes may underlie the clinical features for the 17q25.3 duplication.

Identification of a de novo MAP2K1 gene variant in an affected patient with Cardio-facio-cutaneous syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genotype-phenotype correlation of Cardio-facio-cutaneous syndrome (CFCS) caused by MAP2K1 gene variants.@*METHODS@#Genomic DNA was extracted from peripheral blood sample from a child patient and his parents. Whole exome sequencing (WES) was carried out for the patient. Suspected variant was verified by Sanger sequencing.@*RESULTS@#The patient was a 1-year-8-month old Chinese male who manifested short stature, psychomotor retardation, relative macrocephaly, distinctive facial features, and congenital heart disease. WES test revealed a heterozygous missense c.389A>G (p.Tyr130Cys) variant in the MAP2K1 gene. Sanger sequencing has confirmed the variant as de novo. According to ACMG/AMP guidelines, the variant was classified as pathogenic.@*CONCLUSION@#Compared with previously reported CFCS cases due to MAP2K1 variants. The patient showed obvious behavioral problems, good appetite and tricuspid regurgitation, which may to be novel features for CFCS.

Identification of a 17q25.3 duplication in a Chinese patient with global developmental delay and multiple congenital anomalies / 中华医学遗传学杂志

OBJECTIVE@#To delineate the clinical features,inheritance pattern, and genotype-phenotype correlation of a Chinese patient with a 17q25.3 duplication.@*METHODS@#Whole exome sequencing(WES), chromosomal microarray analysis (CMA), chromosomal karyotyping and fluorescence in situ hybridization (FISH) were employed for the analysis of the proband and his family members.@*RESULTS@#A 5.7 Mb duplication at 17q25.3→qter was identified by WES and CMA in the 4-year-old boy with multiple congenital anomalies, which was classified as a clinically pathogenic variant. This duplication was confirmed by FISH, and was inherited from his unaffected mother who carried a balanced translocation. Further study revealed that his grandmother also carried the balanced translocation but had gestated three healthy children and had no abortion history. His uncle also carried the balanced translocation, while his aunt was normal.@*CONCLUSION@#Above results have enriched the clinical phenotypes of 17q25.3 duplication. Genetic counseling was provided for the family. P4HB, ACTG1, BAIAP2 and TBCD genes may underlie the clinical features for the 17q25.3 duplication.

Analysis of 10 patients with duplications of 15q11q13 region and autism features / 中华医学遗传学杂志

OBJECTIVE To analyze the clinical and genetic features of 10 unrelated patients with duplications of 15q11q13 region and autism features.METHODS Karyotyping,chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) were carried out for the patients and their parents.RESULTS Eight patients presented with a supernumerary marker chromosome (SMC) of unknown origin by G-banding analysis and triplication of the 15q11q13 region by high-resolution CMA analysis. Two remaining patients had normal karyotypes but duplications of the 15q11q13 region. All duplications have encompassed the Prader Willi/Angelman syndrome critical region (PWACR). Similar gains in copy number were not detected among the parents of the patients,suggesting a de novo origin for them. Analysis of SNP-array data of the family trios using Chromosome Analysis Suite Software found that the copy number gains have originated from the mothers.The diagnosis of 15q11q13 duplication syndrome was ascertained. For patients with SMC detected by karyotyping analysis,a FISH assay using probes specific for the 15q11q13 region showed that such SMC also derived from chromosome 15q11q13 region and contained two copy numbers, which was consistent with the result of CMA.CONCLUSION Ten patients with autism and 15q11q13 duplications were identified with combined karyotyping, CMA and FISH analysis. A phenotype - genotype correlation was established.

Chromosomal microarray analysis of 2000 pediatric cases / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the feasibility of chromosomal microarray analysis(CMA) for studying the correlation between birth defects and chromosomal aberrations.</p><p><b>METHODS</b>A total of 2000 patients with birth defects were recruited for the CMA testing.</p><p><b>RESULTS</b>Five hundred twenty two patients (26.1%) were found to have chromosomal abnormalities. These included 24 cases with numerical abnormalities, 11 with mosaicisms, and 11 with uniparental disomies. The remaining 476 cases were of well-known microdeletion or microduplication syndromes. The advantage of CMA over conventional karyotyping was demonstrated in many cases.</p><p><b>CONCLUSION</b>As a powerful tool for patients with birth defects, CMA can produce a higher diagnostic yield compared with conventional karyotyping.</p>

Application of chromosomal microarray analysis for a cohort of Chinese patients with spontaneous miscarriage / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the relationship between spontaneous miscarriage and chromosomal aberrations identifiable with chromosomal microarray analysis (CMA).</p><p><b>METHODS</b>A total of 440 product-of-conceptions were collected for the CMA testing.</p><p><b>RESULTS</b>Four hundred and seventeen of 440 specimens (94.7%) were successfully detected, among which 209 (50.1%) were chromosomal abnormalities. One hundred and twenty-nine (61.7%) of the 209 specimens were numerical chromosomal abnormalities, 40 specimens (19.1%) were structural anomalies, 38 specimens (18.1%) were mosaicisms, and 2 specimens (1.0%) showed regions of homozygosity.</p><p><b>CONCLUSION</b>CMA analysis of products of-conception specimens can yield a higher diagnostic rate than conventional karyotyping. The identification of the cause of spontaneous miscarriage can facilitate estimation of recurrence risks for future pregnancies.</p>

Strategy of laparoscopy and choledochoscopy or duodenoscopy for the treatment of cholecystolithiasis combined with choledocholithiasis / 中华消化外科杂志

Cholecystolithiasis combined with choledocholithiasis is a common disease.The typical open surgery is challenged by the minimally invasive surgery recently.The minimally invasive surgery combined with laparoscopy and choledochoscopy or duodenoscopy has been accepted widely through analyzing and summarizing comprehensively the current situation of the minimally invasive surgery for cholecystolithiasis combined with choledocholithiasis.Laparoscopic cholecystectomy (LC) +endoscopic sphincterotomy (EST) or endoscopic papillary balloon dilation (EPBD) should be chosen primarily for the patients with cholecystolithiasis combined with choledocholithiasis and without common bile duct dilatation (common bile duct diameter ＜0.8 cm),and LC + laparoscopic transcystic common bile duct exploration and lithotomy are used under favorable conditions.LC + choledocholithotomy or T tube drainage should be chosen primarily for the patients with cholecystolithiasis combined with choledocholithiasis and common bile duct dilatation (common bile duct diameter ＞ 0.8 cm).Primary suture of common bile duct should be used with removal of the common bile duct stones,patency of distal common bile duct and recovery function of sphincter of Oddi.The minimally invasive surgery combined with laparoscopy and choledochoscopy or duodenoscopy which is selected reasonably could improve the treatment of cholecystolithiasis combined with choledocholithiasis and reduce the complications,with a significant clinical efficacy.

The mutation and expression of MUS81 gene in laryngeal squamous cell carcinoma / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association of mutations and expression of MUS81 gene with the tumorigenesis and progression of laryngeal squamous cell carcinoma (LSCC).</p><p><b>METHODS</b>PCR-SSCP and DNA sequencing were carried out to examine mutations at exons 9 and 10 of MUS81 gene in 42 LSCC samples, with paired adjacent normal laryngeal tissues (PANLs) as control. Semi-quantitative RT-PCR and Western blot were used to detect the expression of MUS81 gene in the specimens.</p><p><b>RESULTS</b>No mutation was detected in the control group. Among the 42 LSCC specimens, nineteen (45.2%) were found to harbor mutations, including 11(26.2%) occurring within exon 9, and 8 (19%) within exon 10. Seventeen (40.48%) samples showed lower mRNA level of the MUS81 gene (P<0.01), and same proportion of samples had lower protein level (P<0.01), suggesting that MUS81 gene was similarly down-regulated at both mRNA and protein levels in the LSCC samples. Furthermore, mutations of MUS81 gene did not significantly correlate with TNM stages, age and lymphoid node metastasis (P>0.05). Nor did the expression of MUS81 gene with the TNM stages, age and lymphoid node metastasis in LSCC (P>0.05).</p><p><b>CONCLUSION</b>Mutations and abnormal expression of MUS81 gene in the LSCC tissues were observed, which suggested that abnormalities of MUS81 gene may play an important role in the tumorigenesis of LSCC.</p>