Objective:To observe and analyze the pathogenic gene types and clinical phenotypes of Leber congenital amaurosis (LCA).Methods:A retrospective clinical study. Six patients with LCA confirmed by genetic testing and 18 family members were included in the study. The patients came from six unrelated families. The family was investigated with a specific hereditary eye disease enrichment panel which contained 463 known pathogenic genes and based on targeted exome capture technology first to indentify the potential pathogenic genes and mutations. Then the TULP1 , RPGRIP1 , GUCY2D pathogenic mutations were conformed by Sanger sequencing. The pathogenicity of the gene variation was searched through relevant databases and PubMed literature, and its function was explained by protein prediction software. Results:Of the 6 patients, 3 were males and 3 were females; the age was from 3 to 33 years. Nystagmus, finger pressing eyes, photophobia, and night blindness were seen in 5 cases; electroretinogram showed 3 cases of extinction or near extinction; and 4 cases of retinopathy. The results showed patients with compound heterozygous mutation of c.1318C> T and c.1142T> G, homozygous mutation ofc.1318C> T and compound heterozygous mutation of c.1153G> A and c.1561C> T of TULP1 in Family 1, Family 2 and Family 5, respectively. There were compound heterozygous mutations of RPGRIP1 c.391delG and c.1468-2A> G in Family 3 and c.715delA and c.1765C> T in Family 6, respectively. Homozygous mutation of c.3177_3178delAC of GUCY2D was found in Family 4.The parents of all six patients were carriers of corresponding heterozygous mutations. TULP1 gene c.1142T> G, RPGRIP1 gene c.391delG, c.715delA and c.1765C> T and GUCY2D gene c.3177_3178delAC mutations were novel mutations and unreported. The 381th amino acid locus of product protein of TULP1 gene was highly conserved among species. The protein prediction software predicted that the mutation pathogenic. The c.391delG, c.715delA and c.1765C> T mutations of RPGRIP1 gene and c.3177_3178delAC mutation of GUCY2D gene can lead to early translation termination of their product proteins, which are pathogenic variants. Conclusion:The pathogenic mutations of TULP1, RPGRIP1 and GUCY2D genes led to LCA 15, LCA 6 and LCA 1 in six families.

OBJECTIVETo explore the genetic difference between mild cognitive impairment (MCI) and Alzheimer's disease (AD) through association analysis of whole genome sequencing data.

METHODSSequence data of 168 AD patients, 380 MCI patients and 261 elderly controls from the Alzheimer's Disease Neuroimaging Initiative (ADNI) project was collected. The genotype and phenotype association was analyzed through genome wide association study (GWAS).

RESULTSSixteen single nucleotide polymorphisms (SNPs) were found to be associated with AD, and most of them were located on chromosome 19. This was consistent with the results of previous studies. Ten SNP loci were associated with MCI, and most of them were located on chromosome 9. The biological pathways associated with the SNP sets were calculated with a Plink Sets-based algorithm, and the results showed that the SNP loci sets associated with MCI and AD belonged to different biological pathways.

CONCLUSIONThe strictly adjusted result indicated that the SNP loci significantly associated with MCI and AD are different, and the nominal significant associated SNP loci showed that steady MCI and AD shared just a limited number of loci. This indicated that MCI and AD are different diseases bearing distinct genetic risks.

OBJECTIVE: To explore the genetic basis for an infant featuring developmental delay, hand deformity and hypertonia of extremities. METHODS: Clinical data and peripheral blood samples of the proband and her parents were collected. Following DNA extraction, potential mutations were screened on an Ion PGM platform using a gene panel. Suspected mutation was verified by PCR and Sanger sequencing. RESULTS: A novel heterozygous nonsense mutation, c.2521C>T(p.R841X), was identified in the NIPBL gene. The mutation may cause premature termination of translation of the adhesion protein loading factor at 841st amino acids. The same mutation was not found in her parents and 931 healthy controls, and was absent from public databases including ExAC and 1000G. Bioinformatic analysis suggested the mutation to be disease causing. CONCLUSION The c.2521C>T (p.R841X) mutation of the NIPBL gene probably underlies the Cornelia De Lange syndrome in the infant. Prenatal diagnosis may be provided to this family upon their subsequent pregnancy.
De Lange Syndrome ; diagnosis ; genetics ; Female ; Heterozygote ; Humans ; Infant ; Mutation ; Pregnancy ; Prenatal Diagnosis ; Proteins ; genetics

OBJECTIVE: To explore the genetic basis for a family affected with mental retardation combined with autism. METHODS: For the family featuring X-linked recessive inheritance of mental retardation combined with autism, clinical data and peripheral blood samples were collected. Potential mutations of genes associated with intellectual impairment were sequenced with an Ion PGM platform. Suspected mutations were verified with a PCR-Sanger sequencing method. RESULTS: The patient with mental retardation had mild abnormal electroencephalograph(EEG), while brain MRI and CT scans showed no obvious abnormality. Two ABC (autism behavior checklist) testing scores were 73 and 66 when he was 7- and 13-year-old, respectively. A novel hemizygous mutation, c.64C>T (p.L22F), was detected in the GRIA3 gene in the patient, for which his mother was a heterozygous carrier. The mutation site was predicted to be possibly damaging and disease causing by PolyPhen_2 and MutationTaster. CONCLUSION The novel hemizygous c.64C>T (p.L22F) mutation of the GRIA3 gene probably underlies the phenotypes of mental retardation combined with autism in this family. Considering the variable clinical manifestation of mental retardation and genetic heterogeneity of autism, genetic testing is essential for making the correct diagnosis.
Adolescent ; Autistic Disorder ; genetics ; Child ; Humans ; Intellectual Disability ; genetics ; Male ; Mental Retardation, X-Linked ; genetics ; Mutation ; Receptors, AMPA ; genetics

Objective: To explore the genetic basis for a boy with mental retardation. Methods: Clinical data and peripheral blood samples of the family were collected. Potential variants were screened by using a panel for genes associated with intellectual impairment. Suspected variants were verified by PCR and Sanger sequencing. Results: The child presented with mental retardation, language delay and poor self-care. Imaging analysis showed widening of brain fissures and subarachnoid space, and dysplasia of corpus callosum. Three novel heterozygous variants, namely c. 1705T>C(p.S569P), c. 1708dupC (p.R570Pfs*80) and c. 2273delA (p.N758Tfs*22), were identified in the TRAPPC9 gene. The mother of the proband has carried the c. 1708dupC (p.R570Pfs*80) and c. 1705T>C(p.S569P) variants, while his father has carried the c. 2273delA (p.N758Tfs*22) variant. Conclusion The compound heterozygous variants of the TRAPPC9 gene probably underlie the disease in this family. Considering the clinical and genetic heterogeneity of mental retardation, genetic testing is essential for attaining diagnosis for patients with the relevant phenotype.

OBJECTIVE: To analyze the clinical manifestations and causative gene variants of the choroideremia patients, and to help the patients bedifferential diagnosed by whole exome sequencing and provide theoretical basis for their genetic counseling. METHODS: Clinical data of 3 families were collected and genomic DNA was extracted respectively from peripheral blood of patients and related subjects. Exome targeted sequencing was used to screen suspicious gene mutations. Sanger sequencing and quantitative PCR were used to verify the candidate mutations and investigate the mutation carrying status of other members of the family. The candidate mutations were searched through HGMD and PubMed databases for the pathogenicity reports, and the pathogenicity of candidate mutations was judged according to a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. RESULTS: The proband of family 1 is c.1584_1587del (p.Val529Hisfs*6) variant hemizygote, whose daughter carries c.1584_1587del (p.Val529Hisfs*6) heterozygous variation. The proband of family 2 is a hemizygote with deletion of exons 10 to 15 (E10-15del), and her mother and sister carry the E10-15del heterozygous variation. In family 3, the proband is c.544delT (p.Cys182Valfs*14) variant hemizygote, and his mother is c.544delT (p.Cys182Valfs*14) heterozygote, but the father do not detect this variant. All the 3 families were detected pathogenic gene variations of CHM, two of which were known pathogenic variation and one of which was novel CHM gene c.544delT (p.C182Vfs*14) in this study. The c.544delT frameshift mutation of CHM gene can lead to the premature termination of the product protein translation and nonfunctioning protein. It is a pathogenic mutation according to ACMG guidelines. CONCLUSION The findings of this study expand the gene variation spectrum of choroideremia.
Choroideremia/genetics* ; Female ; Heterozygote ; Humans ; Mutation ; Pedigree ; Whole Exome Sequencing

Objective: To explore the genetic basis for an infant featuring developmental delay, hand deformity and hypertonia of extremities. Methods: Clinical data and peripheral blood samples of the proband and her parents were collected. Following DNA extraction, potential mutations were screened on an Ion PGM platform using a gene panel. Suspected mutation was verified by PCR and Sanger sequencing. Results: A novel heterozygous nonsense mutation, c. 2521C>T(p.R841X), was identified in the NIPBL gene. The mutation may cause premature termination of translation of the adhesion protein loading factor at 841st amino acids. The same mutation was not found in her parents and 931 healthy controls, and was absent from public databases including ExAC and 1000G. Bioinformatic analysis suggested the mutation to be disease causing. Conclusion The c. 2521C>T (p.R841X) mutation of the NIPBL gene probably underlies the Cornelia De Lange syndrome in the infant. Prenatal diagnosis may be provided to this family upon their subsequent pregnancy.

OBJECTIVE: To perform prenatal diagnosis for a woman carrying a balanced translocation. METHODS: Clinical phenotype of the woman and her first child was analyzed. Peripheral blood sample of the woman and amniotic fluid sample from two subsequent pregnancies were subjected to chromosomal karyotyping and copy number variation analysis through next-generation sequencing (NGS). RESULTS: The karyotypes of the woman and her first child were determined as 46,XX,t(5;6)(p15:p23) and 46,XX,?der(5),t(5;6)(p15.32;p22.3), respectively. The karyotype of the amniocyte from her second pregnancy was 46,XN,t(5;6)(p15:p23). No pathogenic copy number variation was detected. The karyotype of her third pregnancy was 46,XN,?der(5),t(5;6)(p15.32;p22. 3), in addition with a 6.04 Mb deletion at 5p15.33p15.32 (20 000 - 6 060 000) and a 18.50 Mb duplication at 6p25.3p22.3 (160 000 - 18 660 000). CONCLUSION Combined karyotyping analysis and NGS has enabled detection of fetal copy number variations for a woman carrying a balanced chromosomal translocation.
Child ; DNA Copy Number Variations ; Female ; Fetus ; High-Throughput Nucleotide Sequencing ; Humans ; Karyotype ; Karyotyping ; Pregnancy ; Prenatal Diagnosis

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with microphthalmia. METHODS: Clinical data of the proband was collected. Whole exome sequencing (WES) was carried out to screen potential pathogenic variants in the proband. Candidate variant was verified by Sanger sequencing of the proband and his family members. Pathogenicity of the variant was predicted by searching the PubMed database and bioinformatic analysis. Sanger sequencing of amniotic fluid sample was carried out for prenatal diagnosis. RESULTS: The proband and his father were found to harbor a heterozygous c.151C>G (p.R51G) variant of the MAB21L2 gene. The same variant was not found in his mother and grandparents. Based on the guidelines of American College of Medical Genetics, the c.151C>G (p.R51G) variant was predicted as likely pathogenic. CONCLUSION The c.151C>G (p.R51G) variant of the MAB21L2 gene probably underlay the microphthalmia in the proband. Above finding has facilitated prenatal diagnosis for this pedigree.
China ; Coloboma ; Eye Proteins ; Female ; Humans ; Intracellular Signaling Peptides and Proteins ; Microphthalmos/genetics* ; Mutation ; Osteochondrodysplasias ; Pedigree ; Pregnancy ; Prenatal Diagnosis

Neurological disorders comprise a variety of complex diseases in the central nervous system, which can be roughly classified as neurodegenerative diseases and psychiatric disorders. The basic and translational research of neurological disorders has been hindered by the difficulty in accessing the pathological center (i.e., the brain) in live patients. The rapid advancement of sequencing and array technologies has made it possible to investigate the disease mechanism and biomarkers from a systems perspective. In this review, recent progresses in the discovery of novel risk genes, treatment targets and peripheral biomarkers employing genomic technologies will be dis-cussed. Our major focus will be on two of the most heavily investigated neurological disorders, namely Alzheimer’s disease and autism spectrum disorder.