Inborn errors of metabolism(IEM)are a large class of genetic diseases caused by congenital metabolic disturbance.IEM results in complex clinical phenotype and it is an important cause of disability,death,and stupidity for the children.The technique of reproductive intervention including prenatal diagnosis(PND)or preimplantation genetic diagnosis(PGD)is an important approach to avoid the birth of defect.According to the two basic characteristics of IEM,metabolic disturbance and gene mutation,the clinical application of PND/PGD technology in IEM are reviewed,and put forward a new idea for reproductive intervention based on carrier screening.

OBJECTIVETo determine the karyotype of a cryptic structural abnormality and explore the mechanism of apparent chromosomal terminal deletion.

METHODSFluorescence in situ hybridization(FISH) with a whole chromosome 7 painting probe and a 7q subterminal probe (7q36-->qter), prepared by chromosome microdissection technique, was used to analyze a case with a history of spontaneous abortion and 7q terminal deletion detected by conventional G-banding technique.

RESULTSThe case was a maternal cryptic insertional translocation between chromosome region 1p32 and 7q32-->q35. The region of chromosome 7q36-->qter was not inserted in to chromosome 1, and the abnormal chromosome 7 was not a terminal deletion but an interstitial deletion.

CONCLUSIONSChromosome insertion of the terminal region retains its telomere, which is consistent with the concept of a three-break rearrangement. Interstitial deletion may be regarded as another mechanism for terminal deletion in the chromosome banding level. Combined with chromosome microdissection, FISH technique could be a powerful diagnostic tool for detecting chromosome structural abnormalities.

Adult ; Chromosome Aberrations ; Chromosomes, Human, Pair 1 ; Chromosomes, Human, Pair 7 ; Female ; Humans ; In Situ Hybridization, Fluorescence ; methods

OBJECTIVETo determine the molecular etiology for a muscular dystrophy pedigree with target region sequencing platform using hereditary myopathy capture array.

METHODSSpecific gene testing was performed based on the clinical diagnosis. Since no pathogenic mutation was found, target region sequencing with hereditary myopathy capture array combined with Sanger sequencing and bioinformatics analysis were employed in turn. PolyPhen and NCBI were used to evaluate the pathogenicity of identified mutation and conservation of the gene.

RESULTSTarget region sequencing indicated the proband has carried a heterozygous c.3353 A>C mutation of COL6A3 gene, which was confirmed by Sanger-sequencing in 4 affected individuals from the family. The same mutation was not detected in healthy members of the pedigree. Bioinformatics analysis suggested that the mutation has caused a highly pathogenic amino acid substitution from Histidine to Proline. The affected patients featured normal intelligence with mild myogenic damage by muscle biopsy, slightly increased serum creatine kinase and slow disease progression, which was consistent with Bethlem myopathy.

CONCLUSIONTarget region sequencing is an effective and efficient method for genetic testing. The heterozygous c.3353A>C mutation in exon 8 of the COL6A3 gene probably underlies the Bethlem myopathy with autosomal dominant inheritance.

Adult ; Amino Acid Sequence ; Amino Acid Substitution ; Base Sequence ; Collagen Type VI ; genetics ; Contracture ; genetics ; Exons ; Female ; Heterozygote ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Muscular Dystrophies ; congenital ; genetics ; Mutation, Missense ; Pedigree ; Young Adult

OBJECTIVETo determine the molecular etiology for a Chinese pedigree affected with epidermolysis bullosa simplex (EBS).

METHODSTarget region sequencing using a hereditary epidermolysis bullosa capture array combined with Sanger sequencing and bioinformatics analysis were used. Mutation taster, PolyPhen-2, Provean, and SIFT software and NCBI online were employed to assess the pathogenicity and conservation of detected mutations. One hundred healthy unrelated individuals were used as controls.

RESULTSTarget region sequencing showed that the proband has carried a unreported heterozygous c.1234A>G (p.Ile412Val) mutation of the KRT14 gene, which was confirmed by Sanger sequencing in other 8 affected individuals but not among healthy members of the pedigree. Bioinformatics analysis indicated that the mutation is highly pathogenic. Remarkably, 3 members of the family (2 affected and 1 unaffected) have carried a heterozygous c.1237G>A (p.Ala413Thr) mutation of the KRT14 gene, which was collected in Human Gene Mutation Database (HGMD). Bioinformatics analysis indicated that the mutation may not be pathogenic. Both mutations were not detected among the 100 healthy controls.

CONCLUSIONThe novel c.1234A>G(p.Ile412Val) mutation of the KRT14 gene is probably responsible for the disease, while c.1237G>A (p.Ala413Thr) mutation of KRT14 gene may be a polymorphism. Compared with Sanger sequencing, target region capture sequencing is more efficient and can significantly reduce the cost of genetic testing for EBS.

Adult ; Amino Acid Sequence ; Case-Control Studies ; Epidermolysis Bullosa Simplex ; genetics ; Female ; Humans ; Keratin-14 ; genetics ; Male ; Mutation ; genetics ; Pedigree ; Young Adult

OBJECTIVETo explore the genetic etiology for two Chinese families affected with hypergonadotropic amenorrhea and normal number of antral follicles.

METHODSPeripheral venous blood samples were collected from the families for the extraction of genomic DNA. Mutations of FSHR and LHCGR genes were screened using PCR and Sanger sequencing. Suspected pathogenic mutations were verified in other members of the families. Bioinformatics software and NCBI were used to analyze the pathogenicity of the mutations.

RESULTSTwo previously unreported homozygous mutations, c.419delA and c.1510C>T of the FSHR gene were found in the probands of family I and II, respectively. Pedigree and bioinformatics analysis suggested that both mutations were pathogenic. Literature review suggested that both families were affected with resistant ovary syndrome rather than premature ovarian failure.

CONCLUSIONTwo novel mutations of the FSHR gene have been identified, which have enriched the spectrum of FSHR gene mutations and provided a basis for genetic counseling and direction for reproduction.

Adolescent ; Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; China ; Female ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Ovarian Diseases ; diagnosis ; genetics ; Pedigree ; Receptors, FSH ; genetics ; Young Adult

OBJECTIVETo analyze the karyotypes and SRD5A2 gene mutations in 25 patients with sporadic or familial hypospadias.

METHODSThe patients included 10 adults and 15 children, whose chromosomes were analyzed by G-banded karyotyping, and the SRD5A2 genes were sequenced.

RESULTSTwo patients were found to have an abnormal karyotype, while eight have carried compound heterozygous mutations of the SRD5A2 gene, which included 5 genotypes formed by 6 types of mutations, i.e., p.G203S/p.R227Q, p.R227Q/p.R246Q, p.Q6X/p.Q71X, p.L20P/p.G203S, and p.Q71X/p.R227Q. Mutations of the SRD5A2 gene were present in 32% (8/25) of all patients, 35% (8/23) in those with a normal karyotype, and 44.4% (8/18) in those with proximal type hypospadia. Bioinformatic analysis, literature review and pedigree analysis confirmed that all such mutations are pathogenic.

CONCLUSIONChromosomal anomalies and mutations of the SRD5A2 gene are the main cause of hypospadias. Sequencing of the SRD5A2 gene may explain the etiology of nearly half of the patients with proximal type of hypospadas but a normal karyotype, which can facilitate genetic consulting.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase ; genetics ; metabolism ; Adolescent ; Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Child, Preschool ; Female ; Humans ; Hypospadias ; enzymology ; genetics ; Infant ; Infant, Newborn ; Karyotyping ; Male ; Membrane Proteins ; genetics ; metabolism ; Mutation ; Young Adult

OBJECTIVETo investigate the clinical and molecular genetics characteristics of a patient with mild androgen insensitivity syndrome (MAIS).

METHODSClinical data of the patient was collected, and DNA was isolated from peripheral blood sample. Eight exons of AR gene were amplified by PCR with specific primers and directly sequenced by Sanger method. The results were compared with standard sequences from GenBank. Online Polyphen-2 software was applied to predict the effect of mutation on the protein function and compare the conservation of the sequence at the mutation site in various species. The exon of the AR gene containing the mutated site was analyzed in 90 unrelated normal males using PCR and restrictive digestion with Sfa NI.

RESULTSSequence analysis has detected a novel missense mutation in codon 176 of exon 1 (Ser176Arg) of the AR gene. Analysis with polyphen-2 software has indicated the codon to be highly conserved across various species, and that the S176A mutation has caused damage to the protein structure and function (prediction score=0.999). The same mutation was not detected in 90 healthy males.

CONCLUSIONThe S176A mutation of the AR gene may contribute to the mild androgen insensitivity syndrome.

Adult ; Amino Acid Sequence ; Androgen-Insensitivity Syndrome ; genetics ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Receptors, Androgen ; genetics

OBJECTIVETo investigate the phenotype-genotype association of isodicentromere Y chromosome by analysis of two female patients carrying the chromosome with sexual development disorders.

METHODSThe karyotypes of the two patients were determined by application of conventional G banding of peripheral blood samples and fluorescence in situ hybridization (FISH). PCR was applied to detect the presence of SRY gene.

RESULTSConventional karyotype analysis showed case 1 to be a mosaic: mos.45,X[38]/46,X,+mar[151]/47,XY,+mar[5]/47,X,+mar × 2[2]/46,XY[4], FISH showed that 12 different cell lines were presented in the karyotype of case 1 and partial cell lines with SRY gene, the marker is an isodicentromere Y chromosome [idic(Y)(p)]. No mutation was found in the SRY gene. The karyotype of case 2 was mos.45,X[25]/46,X,+mar[35]. FISH showed the marker to be an idic(Y)(p) without the SRY gene.

CONCLUSIONThe karyotype of patients carrying idic(Y)(p) seems unstable, and female patients have the characteristics of short stature and secondary sexual hypoplasia. Karyotype analysis combined with FISH analysis can accurately determine the breakpoint of idic(Y) and identify the types of complex mosaic, which may facilitate genetic counseling and prognosis.

Adolescent ; Child ; Chromosomes, Human, Y ; Disorders of Sex Development ; genetics ; Female ; Humans ; Karyotype ; Sex Chromosome Aberrations ; Sex-Determining Region Y Protein ; genetics

OBJECTIVETo assess the association of PEX10 gene and 1p36 copy number variations in 1p36 region with concurrent epilepsy through analyzing 3 cases.

METHODSThe karyotypes of 3 patients were determined by high resolution chromosome banding, multiplex ligation dependent probe amplification (MLPA), fluorescence in situ hybridization (FISH) combined with single nucleotide polymorphism array (SNP) technology. Real-time PCR was carried out to determine the mRNA levels of PEX10 gene in peripheral blood of the patients.

RESULTSNo abnormality was found upon high resolution karyotyping. MLPA analysis showed that all of the 3 patients had a copy number variation of subtelomeric region in the short arm of chromosome 1, which was confirmed by FISH and SNP chip analyses. Case 1 and case 2 both had an epilepsy phenotype, and their copy number variations have encompassed the PEX10 gene. On the other hand, case 3 has absent epilepsy, and its PEX10 gene copy number was normal. Family investigation confirmed that the chromosome abnormalities in all of the 3 cases were of de novo type. Compared with healthy controls, real-time PCR showed that mRNA of the PEX10 gene was increased in case 1 but decreased in case 2.

CONCLUSIONThe abnormal expression of PEX10 gene resulting from copy number variations of 1p36 region may be associated with the epilepsy phenotype.

Child ; Chromosomes, Human, Pair 1 ; DNA Copy Number Variations ; Epilepsy ; genetics ; Female ; Humans ; Peroxins ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Receptors, Cytoplasmic and Nuclear ; genetics

Chromosomal translocation is a kind of common chromosomal abnormality. The carriers with chromosomal translocation could have more chance of normal pregnancy with the help of fluorescence in situ hybridization(FISH). This is a review aimed at analyzing the meiosis types of the translocation chromosome. The strategy of preimplantation genetic diagnosis for the carriers with chromosomal translocation is also discussed.
Humans ; In Situ Hybridization, Fluorescence ; methods ; Meiosis ; genetics ; Preimplantation Diagnosis ; methods ; Translocation, Genetic ; genetics