Toftkappel7853

OBJECTIVE To analyze INS gene variant in a patient with maturity-onset diabetes of the young type 10. METHODS High-throughput sequencing was used to screen for the variants. Suspected variant was verified by Sanger sequencing. RESULTS Genetic testing indicated that the patient and his mother have both carried a heterozygous c.130G>A (p.Gly44Arg) variant in exon 1 of the INS gene. Prediction of protein structure suggested the variant to be pathogenic. CONCLUSION The c.130G>A (p.Gly44Arg) variant of the INS gene probably underlies the disease in this patient.OBJECTIVE To explore the genetic basis for a Chinese neonate with lipoprotein lipase deficiency. METHODS Targeted capture and next-generation sequencing (NGS) were carried out to detect variants of genes associated with inborn errors of metabolism. Suspected variants were validated by Sanger sequencing. RESULTS Genetic testing revealed novel complex heterozygous variants, namely c.347G>C (p.Arg116Pro) and c.472T>G (p.Tyr158Asp), of the LPL gene, which were respectively inherited from his father and mother. CONCLUSION Compound heterozygous variants c.347G>C and c.472T>G of the LPL gene probably underlie the lipoprotein lipase deficiency in this child.OBJECTIVE To detect variants of ARSA gene in a child featuring late infantile metachromatic leukodystrophy (MLD). METHODS PCR and Sanger sequencing was carried out for the patient and her parents. RESULTS The patient had typical features of MLD including ARSA deficiency, regression of walking ability, and demyelination. Compound heterozygous variants of the ARSA gene, namely c.960G>A and c.244C>T, were detected in the patient, for which her mother and father were respectively heterozygous carriers. ARSA c.960G>A was known to be pathogenic, while ARSA c.244C>T was a novel variant. The same variants were not detected among 50 healthy controls. CONCLUSION The compound heterozygous variants c.960G>A and c.244C>T of the ARSA gene probably underlie the MLD in this patient.OBJECTIVE To identify pathological mutation of D4Z4 in a child with facioscapulohumeral muscular dystrophy (FSHD) presented initially as mental retardation. METHODS Wechsler Intelligence Scale for Children Revised in China (WISC-IV) was used to assess the patient's IQ. Other clinical data was also collected. With genomic DNA extracted from peripheral blood samples, the child and his parents were subjected to medical exome sequencing and copy number variation analysis by next generation sequencing (NGS). The D4Z4 repeats and their origin source were determined by molecular combing. RESULTS By the WISC-IV test, the child was found to have a total IQ of 41, with a speech comprehension IQ of 45, and perceptual inference index IQ of 52. No pathological mutation was detected by NGS. By molecular combing method, the child was found to carry a D4Z4 spanning 5.2 kb with a copy number of 2. Analysis of his parents indicate that the mutation was de novo. CONCLUSION The D4Z4 copy number variation may account for the FSHD and mental retardation in the child. The molecular combing method can be used to identify the number of repeat units and facilitate the diagnosis of FSHD.OBJECTIVE To explore the genetic etiology of a girl featuring epilepsy, speech delay and mild mental retardation. METHODS Peripheral blood samples of the child and her parents were collected. Genomic DNA was extracted and subjected to next generation sequencing. Suspected variant was confirmed by Sanger sequencing. RESULTS The child was found to carry a de novo heterozygous c.3592G>A (p.V1198M) variant of the SMARCA2 gene, which was predicted to be pathogenic by bioinformatic analysis. CONCLUSION The child was diagnosed with Nicolaides-Baraitser syndrome due to heterozygous variant of the SMARCA2 gene.OBJECTIVE To explore the genetic basis for a newborn infant suspected with Donohue syndrome. METHODS Whole exome sequencing (WES) was used to screen potential variants in the child. Suspected variants were validated through Sanger sequencing and real-time PCR. RESULTS The child was found to carry two heterozygous variants in the INSR gene, including c.3258+4(IVS17)A>G and deletion of exon 2, which were respectively inherited from her mother and father. CONCLUSION The compound heterozygous variants of the INSR gene probably underlie the disease in this patient.OBJECTIVE To detect potential variant in a male fetus suspected for Ectrodactyly, Ectodermal dysplasia, Cleft lip/palate (EEC) syndrome. METHODS Peripheral blood samples of the fetus and his parents were collected for the extraction of DNA. Whole-exome sequencing was carried out to detect potential variants. Suspected variants were verified by Sanger sequencing. RESULTS The fetus was found to carry a heterozygous c.673C>T missense variant of the Tp63 gene, which was known to underlie split-hand/split-foot malformation. The same variant was not found in either parents. CONCLUSION The heterozygous c.673C>T missense variant of the Tp63 gene probably underlies the EEC syndrome in the fetus. Above finding also expanded the phenotypic spectrum for this variant.OBJECTIVE To assess the value of non-invasive prenatal screening (NIPS) for the detection of fetal chromosome 16 aneuploidy through multi-method verification and follow-up of pregnancy outcomes. METHODS From January 2016 to December 2017, 7972 pregnant women with singleton pregnancies accepted the NIPS test after 10th gestational week with informed consent. Those with fetal chromosome 16 abnormality suggestive by the NIPS test were subjected to prenatal diagnosis including chromosomal karyotyping and chromosomal microarray analysis (CMA). RESULTS Of the 7972 pregnant women tested by NIPS, 16 (0.2%) were predicted to have fetal chromosome 16 abnormality. The average age of the 16 pregnant women was 33.5 ± 5.24, and the average gestational week was 19.88±2.47. Chromosomal karyotyping verified that 3 fetuses had mosaicisms and 1 carried pericentric inversion of chromosome 9, which yielded a positive predictive value (PPV) of 18.8%. CMA has detected 7 fetuses with genomic abnormalities, which yielded a PPV of 43.8%. Eleven of the 16 women (68.8%) have given birth to healthy babies. CONCLUSION For pregnant women with a high risk of chromosome 16 aneuploidy suggested by NIPS, the prognosis of fetus should be evaluated by multiple methods. Compared with conventional karyotyping analysis, molecular methods such as CMA are far superior.OBJECTIVE To explore the genetic basis for a child featuring severe mental retardation. METHODS The child was subjected to target region capture and next generation sequencing. Suspected variants were verified by Sanger sequencing. RESULTS The child was found to harbor a hemizygous c.1A>G (pMet1?) variation of the ARX gene, for which his mother was a heterozygous carrier. The mutation was unreported previously and was predicted to be "probably pathogenic" by bioinformatic analysis. CONCLUSION The c.1A>G (pMet1?) variant of the ARX gene may underlie the occurrence of severe mental retardation in this child.OBJECTIVE To explore the genetic basis for a child with mentally retardation. METHODS G-banding karyotyping, single nucleotide polymorphism array (SNP-array) and fluorescence in situ hybridization (FISH) were performed for the child. Karyotyping and FISH were also carried out for her parents. RESULTS SNP-array has detected a 5077 kb microdeletion at 5q35.2q35.3 and a 4964 kb microduplication at 7q36.2q36.3 in the child. The results were confirmed by FISH. Based on above results, the father was subsequently found to carry a cryptic t(5;7) (q35.2; q36.2) translocation. The child was verified to have inherited a der(5) t(5;7)(q35.2; q36.2) from her father. CONCLUSION The 5077 kb microdeletion at 5q35.2q35.3 may have predisposed to the Sotos syndrome in the child. SNP-array combined with G-banding karyotyping and FISH can help to detect cryptic chromosomal translocations among patients.OBJECTIVE To detect potential variants of COL1A1 gene in five Chinese pedigrees affected with osteogenesis imperfecta (OI) and provide prenatal diagnosis for a fetus at 11th gestational week. METHODS The coding regions and exon/intron boundaries of 225 genes associated with bone diseases were subjected to targeted capture and next generation sequencing (NGS). Suspected mutations were verified with Sanger sequencing in the probands, unaffected relatives and 100 unrelated healthy controls. Prenatal diagnosis for a high-risk fetus was carried out by Sanger sequencing. RESULTS The probands of the pedigrees 1-5 have respectively carried c.3226G>A (p.Gly1076Ser), c.579delT (p.Gly194Valfs*71), c.2911-2912insAG (p.Gly971Glufs*138), c.3037G>A (p.Gly1013Arg) and c.642+5G>A variants of the COL1A1 gene. For pedigree 1, the same variant was not found in the fetus. compound 3k nmr c.3037G>A (p.Gly1013Arg) and c.2911-2912insAG (p.Gly971Glufs*138) were not reported previously. link2 CONCLUSION Mutations of the COL1A1 gene probably underlie the OI in the five pedigrees. Combined NGS and Sanger sequencing can provide an effective and accurate method for the genetic and prenatal diagnosis of OI.OBJECTIVE To carry out genetic testing and prenatal diagnosis for 90 families affected with spinal muscular atrophy (SMA), and discuss the necessity for carrier screening. METHODS All families were subjected to multiplex ligation-dependent probe amplification (MLPA) analysis. Combined MLPA and allele-specific PCR (AS-PCR) was used for prenatal diagnosis of the pregnant women. RESULTS Among the 90 couples, 84 (93%) had a negative family history, 85 (94%) had given birth to an affected child before. Eighty-five husbands and 88 wives carried heterozygous deletion of exon 7 of the SMN1 gene. Two wives had homozygous deletion of exon 7 of the SMN1 gene and were affected. Prenatal diagnosis showed that 19 fetuses were SMA patients, 48 fetuses were carriers, and 23 fetuses were normal. Of note, eighteen affected fetuses were conceived by couples without a family history, which accounted for 20% of all pregnancies and 95% of all affected fetuses. CONCLUSION To screen SMA carriers using MLPA and carry out prenatal diagnosis using combined MLPA and AS-PCR can ensure accurate diagnosis, which has a significant value for the prevention of SMA affected births.OBJECTIVE To detect ASXL1 gene variants among patients with myelodysplastic syndrome (MDS) and explore their correlation with variants of other genes and clinical features of patients. METHODS For 149 patients with MDS, genomic DNA was amplified by PCR and subject to direct sequencing to identify variants of ASXL1, U2AF1, SF3B1, DNMT3A, TET2, IDH1/2, NPM1, FLT3-ITD and C-KIT genes. RESULTS ASXL1 variants were found among 37 patients (24.8%). Other commonly mutated genes included U2AF1 (22.8%), TET2 (11.4%), DNMT3A (9.4%), NPM1 (8.1%) and SF3B1 (6.0%). The frequency of concurrent U2AF1 and TET2 variants among patients with ASXL1 variants was slightly higher than that of wild-type patients. link3 No significant difference was found in median age, MDS subtype, karyotype, peripheral leukocytes, hemoglobin, platelet levels, and bone marrow blast counts between the ASXL1-variant and the wild-type groups (P> 0.05). Twenty-nine patients harboring ASXL1 variants were followed up, 37.9% progressed to acute myeloid leukemia (AML).