OBJECTIVE: To assess the value of genetic screening by high-throughput sequencing (HTS) for the early diagnosis of neonatal diseases. METHODS: A total of 2 060 neonates born at Ningbo Women and Children's Hospital from March to September 2021 were selected as the study subjects. All neonates had undergone conventional tandem mass spectrometry metabolite analysis and fluorescent immunoassay analysis. HTS was carried out to detect the definite pathogenic variant sites with high-frequency of 135 disease-related genes. Candidate variants were verified by Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA). RESULTS: Among the 2 060 newborns, 31 were diagnosed with genetic diseases, 557 were found to be carriers, and 1 472 were negative. Among the 31 neonates, 5 had G6PD, 19 had hereditary non-syndromic deafness due to variants of GJB2, GJB3 and MT-RNR1 genes, 2 had PAH gene variants, 1 had GAA gene variants, 1 had SMN1 gene variants, 2 had MTTL1 gene variants, and 1 had GH1 gene variants. Clinically, 1 child had Spinal muscular atrophy (SMA), 1 had Glycogen storage disease II, 2 had congenital deafness, and 5 had G6PD deficiency. One mother was diagnosed with SMA. No patient was detected by conventional tandem mass spectrometry. Conventional fluorescence immunoassay had revealed 5 cases of G6PD deficiency (all positive by genetic screening) and 2 cases of hypothyroidism (identified as carriers). The most common variants identified in this region have involved DUOX2 (3.93%), ATP7B (2.48%), SLC26A4 (2.38%), GJB2 (2.33%), PAH (2.09%) and SLC22A5 genes (2.09%). CONCLUSION Neonatal genetic screening has a wide range of detection and high detection rate, which can significantly improve the efficacy of newborn screening when combined with conventional screening and facilitate secondary prevention for the affected children, diagnosis of family members and genetic counseling for the carriers.
Child ; Infant, Newborn ; Humans ; Female ; Prospective Studies ; Connexins/genetics* ; Connexin 26/genetics* ; Glucosephosphate Dehydrogenase Deficiency ; Mutation ; Sulfate Transporters/genetics* ; DNA Mutational Analysis ; Genetic Testing/methods* ; Deafness/genetics* ; Neonatal Screening/methods* ; Hearing Loss, Sensorineural/genetics* ; High-Throughput Nucleotide Sequencing ; Solute Carrier Family 22 Member 5/genetics*

OBJECTIVE: To carry out carrier screening for Spinal muscular atrophy (SMA) in reproductive-aged individuals from Dongguan region and determine the carrier frequency of SMN1 gene mutations. METHODS: Reproductive-aged individuals who underwent SMN1 genetic screening at the Dongguan Maternal and Child Health Care Hospital from March 2020 to August 2022 were selected as the study subjects. Deletions of exon 7 and 8 (E7/E8) of the SMN1 gene were detected by real-time fluorescence quantitative PCR (qPCR), and prenatal diagnosis was provided for carrier couples by multiple ligation-dependent probe amplification (MLPA). RESULTS: Among the 35 145 subjects, 635 were found to be carriers of SMN1 E7 deletion (586 with heterozygous E7/E8 deletion, 2 with heterozygous E7 deletion and homozygous E8 deletion, and 47 with sole heterozygous E7 deletion). The carrier frequency was 1.81% (635/35 145), with 1.59% (29/1 821) in males and 1.82% (606/33 324) in females. There was no significant difference between the two genders (χ² = 0.497, P = 0.481). A 29-year-old woman was found to harbor homozygous deletion of SMN1 E7/E8, and was verified to have a SMN1∶SMN2 ratio of [0∶4], none of her three family members with a [0∶4] genotype had clinical symptoms. Eleven carrier couples had accepted prenatal diagnosis, and one fetus was found to have a [0∶4] genotype, and the pregnancy was terminated. CONCLUSION This study has determined the SMA carrier frequency in Dongguan region for the first time and provided prenatal diagnosis for carrier couples. The data can provide a reference for genetic counseling and prenatal diagnosis, which has important clinical implications for the prevention and control of birth defects associated with SMA.
Humans ; Child ; Pregnancy ; Male ; Female ; Adult ; Homozygote ; Sequence Deletion ; Prenatal Diagnosis ; Genetic Testing ; Muscular Atrophy, Spinal/genetics* ; Survival of Motor Neuron 1 Protein/genetics* ; Genetic Carrier Screening

OBJECTIVE: To establish a screening model for females of reproductive age carrying Duchenne muscular dystrophy (DMD) variants based on a current community health examination platform. METHODS: A total of 61 870 participants were recruited between October 2017 and October 2019. Serum creatine kinase (CK) was measured with a Roche Cobasc 701/702 using an enzymatic rate method. Genetic testing was offered to those with a CK level of ≥ 200 U/L. For carriers of DMD variants, genetic counseling and follow up were provided. RESULTS: For the 61 870 females participating in the program, 1078 were found with raised serum CK (≥ 200 U/L), of which 618 (57.33%) accepted CK re-measurement after at least a two-week interval. One hundred and twenty cases were found with sustained serum CK elevation, of which 6 were confirmed to be definite DMD carriers regardless of family history. Genetic testing was provided to 33 females with a family history for DMD, and 13 were determined as definite carriers. An affected fetus was detected by prenatal diagnosis. After genetic counseling, the parents had opted induced abortion. CONCLUSION Large-scale DMD carrier screening through a three-step approach based on the current community health examination platform is both feasible and cost effective.
Female ; Genetic Carrier Screening ; Genetic Counseling ; Genetic Testing ; Humans ; Muscular Dystrophy, Duchenne/genetics* ; Pregnancy ; Prenatal Diagnosis

OBJECTIVE: To perform carrier screening for spinal muscular atrophy (SMA) among 3049 reproductive-age individuals from Yunnan region and determine the copy number of survival motor neuron (SMN) gene and carrier frequencies. METHODS: Multiplex ligation-dependent probe amplification (MLPA) was used to determine the copy number of exon 7 of SMN1 and SMN2 genes and identify those with a single copy of SMN1 gene. Prenatal diagnosis was performed for couples whom were both found to be SMA carriers. RESULTS: In total 62 SMA carriers were identified among the 3049 subjects, which yielded a carrier frequency of 1 in 49 (2.03%). No statistical difference was found in the carrier frequency between males and females (1.91% vs. 2.30%, P>0.05). Respectively, 1.3% (41/3049) and 0.69% (21/3049) of the carriers were caused by heterozygous deletion and conversion of the SMN1 gene. The average copy number for SMN1 alleles was 1.99. Two couples were found to be both as SMA carriers, for whom the birth of an affected fetus was avoided by prenatal diagnosis. CONCLUSION No difference was found in the carrier frequency of SMA-related mutations between the two genders in Yunnan region, which was in keeping to an autosomal recessive inheritance pattern. Determination of the carrier frequency for SMA and SMN gene variants may provide a basis for genetic counseling and prenatal diagnosis for the disease.
China ; Female ; Genetic Carrier Screening ; Genetic Counseling ; Genetic Variation ; Heterozygote ; Humans ; Male ; Muscular Atrophy, Spinal ; genetics ; Pregnancy ; Prenatal Diagnosis ; Survival of Motor Neuron 1 Protein ; genetics ; Survival of Motor Neuron 2 Protein ; genetics

OBJECTIVE: To detect additional variants for newborn carriers of single heterozygous variants of the GJB2 or SLC26A4 gene by genechip analysis in Changsha area, and explore the variation spectrum of deafness-related genes in this region. METHODS: For 462 newborns carrying single heterozygous variants of the GJB2 or SLC26A4 gene, all exons of the genes were subjected to Sanger sequencing. The pathogenicity of the variants was analyzed by database and literature search. RESULTS: For 305 newborns carrying a heterozygous GJB2 variant, 143 (46.49%) were found to carry additional variants, including 29 (9.51%) with c.109G>A likely pathogenic variant, and 1 (6.48%) with c.551G>A pathogenic variant. Among 153 newborns carrying single heterozygous variant of the SLC26A4 gene, 2 (1.31%) were found with a c.281C>T variant, and 1 (0.65%) with a c.1547_1548ins pathogenic variant. Among 4 newborns simultaneously carrying GJB2 and SLC26A4 variants, two were found to carry c.109G>A and c.844T>C variants (clinical significance unknown), respectively. CONCLUSION For newborns carrying single heterozygous variants of the GJB2 or SLC26A4 gene by genechip analysis, the detection rate for other variants is quite high. Sanger sequencing can significantly improve the detection rate of high-risk newborns and enrich the variant spectrum of deafness genes.
Connexins/genetics* ; DNA Mutational Analysis ; Deafness/genetics* ; Genetic Carrier Screening ; Heterozygote ; Humans ; Infant, Newborn ; Mutation ; Oligonucleotide Array Sequence Analysis ; Sulfate Transporters/genetics*

OBJECTIVE: To explore the effect of chromosomal translocations on the composition of embryonic chromosomes and its mechanism. METHODS: For 52 couples with one partner carrying a chromosomal translocation, results of next generation sequencing of all embryos derived from 61 cycles were divided into different groups based on the type of translocations, gender of the carrier, and maternal age. Effect of parental chromosomal translocations on the composition of embryonic chromosomes of each group was analyzed. RESULTS: A significant difference was found between carriers of reciprocal and Robertsonian translocations in terms of proportion of abnormal embryos and structurally normal chromosomes (63.3% vs. 27.5%, and 1.1% vs. 0.3%, respectively). Compared with male carriers, there was an increase in the rate of abnormalities for female carriers (67.2% vs. 58.3% for reciprocal translocations, and 45.5% vs. 13.8% for Robertsonian translocations). The risk for chromosomal abnormality also increased with the maternal age. No significant difference was found in the proportion of abnormal embryos between carriers divided by involvement of acrocentric chromosomes or terminal chromosomal breakpoints. CONCLUSION The types of parental translocation, gender of carrier, maternal age, and interchromosomal effect have certain effect on the composition of embryonic chromosomes.
Chromosomes, Human ; genetics ; Female ; Genetic Carrier Screening ; Humans ; In Situ Hybridization, Fluorescence ; Male ; Maternal Age ; Pregnancy ; Preimplantation Diagnosis ; Translocation, Genetic

PURPOSE: We examined the prevalence and CGG/AGG repeat structure of expanded alleles of the FMR1 gene in preconceptional and pregnant Korean women. MATERIALS AND METHODS: The CGG repeats in the FMR1 genes of 1,408 women were analyzed by polymerase chain reaction and Southern blot analysis. To estimate the prevalence of expansion alleles, the individuals were divided into low risk and high risk group. RESULTS: Within this population, 98.4% had normal alleles and 1.6% had abnormal alleles including intermediate (0.6%), premutation (0.5%), full mutation (0.1%), and hemizygous (0.4%) alleles. There were 2 premutation alleles (1:666, 95% confidence interval [CI] 1:250-1,776) in the low risk group and 5 premutation alleles (1:15, 95% 1:6-36) in the high risk group. There were 8 intermediate alleles (1:167, 95% CI 1:130-213) in the low risk group and 1 intermediate alleles (1:76, 95% CI 1:11-533) in the high group. Six of the 7 premutation alleles did not contain AGG interruptions within the repeats and 1 had a single AGG interruption. Four of the 9 intermediate alleles contained 2-3 AGG, 4 had a single AGG, and 1 had no AGG interruptions. CONCLUSION: Our study demonstrates the prevalence and CGG/AGG structure of expansion alleles in Korean women. The identified premutation prevalence is higher than that of other Asian populations and lower than that of Caucasian populations. Although our study is limited by size and population bias, our findings could prove useful for genetic counseling of preconceptional or pregnant women.
Alleles ; Asian Continental Ancestry Group ; Bias (Epidemiology) ; Blotting, Southern ; Carrier State ; Female ; Fragile X Syndrome ; Gene Frequency ; Genetic Counseling ; Humans ; Mass Screening* ; Polymerase Chain Reaction ; Pregnant Women ; Prevalence ; Trinucleotide Repeat Expansion

OBJECTIVETo investigate the value of the junction fragments between the breakpoints of introns in identifying deletional Duchenne muscular dystrophy (DMD) carriers.

METHODSA DMD family (including the index patient III2 and the suspected carrier II3) and a sporadic DMD case (including the patient II1 and his mother I2) were studied. The patient III2 of the DMD family was identified as having exons 31-43 deletion of the DMD gene, and the sporadic patient II1 had exons 45-54 deletion. A PCR-based genome-walking method was used to locate the breakpoints in the corresponding introns. The junction fragments of the patients and their female relatives waiting for a diagnosis were amplified by PCR with primers adjacent to the deletion junctions.

RESULTSPCR amplification yielded identical positive results for the female suspected carrier II3 of and the index patient of the DMD family, and the former was thus diagnosed as a carrier of DMD. PCR amplification of the sporadic patient's mother I2 showed a negative result, but the patient II1 had a positive result, so that the patient's mother was excluded as being a carrier of DMD.

CONCLUSIONRoutine PCR technique for detecting the junction fragments allows identification of carriers among female relatives of patients with deletional DMD.

DNA Primers ; Exons ; Female ; Genetic Carrier Screening ; Heterozygote ; Humans ; Introns ; Male ; Muscular Dystrophy, Duchenne ; genetics ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Sequence Deletion

OBJECTIVETo explore the application of preimplantation genetic diagnosis (PGD) for infantile malignant osteopetrosis (IMO).

METHODSFor a family affected with IMO, PGD was provided using combined parental mutation detection and haplotype constructions with microsatellite markers spanning the TCIRG1 gene. Prenatal diagnosis was performed on the chorionic villus and amniocentesis samples by direct sequencing.

RESULTSPrenatal diagnosis showed that the fetus by the third pregnancy has carried the parental mutations [c.242delC (p.Pro81Argfs*85) and c.1114C>T (p.Gln372*)], and the pregnancy was terminated. PGD was subsequently performed through mutations detection and haplotype analyses following whole genome amplification (WGA) of each of 13 cells. The results showed that 6 of the 13 embryos were unaffected, 3 were carriers and 4 were affected. Well developed unaffected/carrier embryos were selected and transferred into the uterus. A single pregnancy was confirmed. Subsequently pre- and post-natal diagnoses have confirmed development of a healthy child.

CONCLUSIONThe study demonstrated the advantage of PGD over prenatal diagnosis when natural pregnancies have repeatedly produced IMO children/fetuses.

Adult ; Base Sequence ; Female ; Fertilization in Vitro ; Fetus ; Genetic Carrier Screening ; Humans ; Infant ; Male ; Microsatellite Repeats ; Molecular Sequence Data ; Osteopetrosis ; diagnosis ; embryology ; genetics ; prevention & control ; Pedigree ; Point Mutation ; Pregnancy ; Preimplantation Diagnosis ; Vacuolar Proton-Translocating ATPases ; genetics

OBJECTIVETo assess the association of copy number variations of SMN1, SMN2, NAIP, GTF2H2 and H4F5 genes with clinical classification of spinal muscular atrophy in children, and determine the copy number of the SMN gene among pregnant women. A carrier screening was also performed in Sichuan province.

METHODSThe copy number variations of the above genes among 53 confirmed SMA patients were determined with MLPA technique. The copy number variations were analyzed by the Fisher's exact test. Deletion of exon 7 in the SMN1 gene was screened with denaturing high performance liquid chromatography (DHPLC) for 427 pregnant women.

RESULTSAmong the 53 cases of type I, II, and III SMA patients, the rate of homozygous deletion of both exons 7 and 8 of the SMN1 gene were 100%, 94.44% and 87.50%, respectively, whereas those of homozygous deletion of exon 7 of SMN1 gene were 0, 5.56%, and 12.50%, respectively. The patients with 1, 2, 3, and 4 copies of exon 7 of the SMN2 gene were 11.32%, 67.92%, 13.21% and 7.55%, respectively. The patients with 0, 1, and 2 copies of exon 5 of NAIP gene were 11.32%, 62.26%, and 26.42%, respectively. No deletion was detected in GTF2H2 or H4F5 genes. The heterozygous loss rate of exon 7 in SMN gene in the pregnant women population of Sichuan region was approximately 2.11%.

CONCLUSIONCopy number variations of SMN2 and NAIP genes in patients are related to SMA clinical types (P < 0.05). In contrast, there was no relationship between SMA clinical types and deletion of exons 7 and 8 in the SMN1 gene (P > 0.05). Analysis of copy number change in SMN1 gene can assist SMA carrier screening. However, when the general population without SMA family history is screened for disease-causing genes, it should be noted that the type "2+0" carriers may affect the screening result, and the result should be interpreted with caution.

Adolescent ; Child ; Child, Preschool ; DNA Copy Number Variations ; Female ; Genetic Carrier Screening ; Humans ; Infant ; Male ; Neuronal Apoptosis-Inhibitory Protein ; genetics ; Spinal Muscular Atrophies of Childhood ; genetics ; Survival of Motor Neuron 1 Protein ; genetics