Prenatal diagnosis and pregnancy outcomes of 17 fetuses with 16p13.11 microdeletion syndrome / 中华围产医学杂志

Objective:To investigate the association between prenatal genotype and phenotype of 16p13.11 microdeletion syndrome, aiming to provide a reference for prenatal diagnosis and genetic counseling.Methods:This retrospective study analyzed the results of comparative genomic hybridization microarray and low-coverage whole genome sequencing performed on 4 230 pregnant women in the Henan Provincial People's Hospital from July 2018 to July 2021. Indications for prenatal diagnosis, pedigree information and pregnancy outcomes of 17 fetuses with 16p13.11 microdeletion were described.Results:Prenatal diagnostic indications in the 17 fetuses were ultrasound abnormalities in five cases (increased nuchal translucency in four and cerebral ventriculomegaly with 10.7 mm in one), inter-twin weight discordance over 20% in one case, high risk in five cases and marginal risk in one in trisomy-21 serum screening, advanced maternal age in three cases (one with echogenic intracardiac focus in the left ventricle and two with normal ultrasound images) and adverse pregnancy history in two cases with normal ultrasound images. Pedigree verification that performed on 12 cases revealed that five were caused by de novo mutations and seven were inherited from their parents. The follow-up results showed that five cases were terminated, two lost to follow-up and 10 born alive (inheritance patterns were de novo mutations in three cases, parental inheritance in six and unknown pattern in one). These 10 infants were followed up from age 7 months to 3 years and 2 months and the results showed that one case was born with choroid plexus cyst of the left ventricle and presented instability of gait at 1 year and 3 months; one was a premature infant with 33 gestational weeks whose parents reported his language ability was not well at 2 years and 1 month old but without other abnormalities; one case had low muscle tone and was unable to keep head upright at 3 months who recovered at 5 months old after rehabilitation treatment according to the parents' report; all seven parents in the remaining seven cases reported no abnormalities. Conclusions:There was no specific prenatal diagnostic indication for 16p13.11 microdeletion syndrome. Genetic tracing, pregnancy outcome analysis and follow-up surveillance would provide reference for genetic counseling of 16p13.11 microdeletion syndrome.

Prenatal diagnosis and genetic analysis of 9p24 microdeletion in six fetuses / 中华围产医学杂志

Objective:To investigate the prenatal diagnosis and genetic analysis of 9p24 microdeletion in six fetuses.Methods:Genetic data of six pregnant women with positive results of serological Down's syndrome screening at Henan Provincial People's Hospital from January 2018 to January 2020 were retrospectively collected and analyzed. Amniotic fluid and the parents' peripheral blood samples were subjected to G banding and array comparative genomic hybridization (aCGH) analysis. Detected copy number variation (CNV) were classified based on the American College of Medical Genetics and Genomics (ACMG) scoring standard.Results:Six fetuses showed no abnormalities in ultrasound during the second trimester as well as in karyotyping. A chromosome deletion of 1 019~6 001 kb at 9p24 was found in all six fetuses by aCGH, referring to disease-related genes DMRT1, SMARCA2, DOCK8, etc. The deletion of case 3 was inherited from the asymptomatic father, and the other fetal five were all de novo mutations. Cases 1, 2, 5, and 6 were pathogenic/likely pathogenic CNV carriers and cases 3 and 4 were CNV of unknown clinical significance carriers. After genetic counseling, cases 1, 2, 5, and 6 chose to terminate the pregnancies; cases 3 and 4 continued and gave birth to normal offspring. Conclusions:Fetuses with 9p24 microdeletion lack specific phenotypes before born. DMRT1 and SMARCA2 may be the key genes in this region.

Genetic analysis of 21 fetuses with high suspicion of congenital skeletal malformation by prenatal ultrasound / 中华围产医学杂志

Objective:To explore the genetic etiology of fetuses with high suspicion of congenital skeletal malformation detected by prenatal ultrasound.Methods:This retrospective study collected 21 pregnant women with highly suspected fetal skeletal malformation indicated by ultrasound (the couples had no skeletal malformation) at Institute of Medical Genetics, Henan Provincial People's Hospital from January 2019 to August 2020. Amniotic fluid/umbilical cord blood of the fetus and peripheral blood of the couples were obtained for karyotype analysis, chromosomal microarray analysis, and whole-exome sequencing. Sanger sequencing was performed for the "pathogenic" "suspected pathogenic" "variants of uncertain significance" variants detected by whole exome sequencing. Genetic etiology of the 21 fetuses was described.Results:A total of five chromosomal abnormalities were detected, including four cases of trisomy 21 and one trisomy 18. Chromosome microarray analysis detected one case of abnormal copy number variation, 16 p11.2 microdeletion syndrome. Ten cases of monogenic diseases were found by whole exome sequencing and eight genes were involved ( SGMS2, FGFR3, DYNC2H1, WDR35, TBX5, COL2A1, FGFR2, and ALPL). Totally, 14 variations were detected, among which seven were novel variations (c.8129T>A, c.7126G>A, c.10307_10320del, and c.2641G>T in DYNC2H1 gene; c.3085G>A and c.491G>A in WDR35 gene; c.1070G>T in COL2A1 gene). Conclusions:For fetus, whose parents have no skeletal malformation, highly suspected of congenital malformation of skeletal system by prenatal ultrasound, genetic factor is the primary reason, including chromosomal abnormalities, copy number variations, and monogenic mutations.

Genetic analysis and prenatal diagnosis of a Chinese pedigree affected with Usher syndrome due to novel compound heterozygous variants of PCDH15 gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical features and genetic variant in a patient with Usher syndrome.@*METHODS@#Whole exome sequencing was carried out for the patient. Suspected variants were validated by Sanger sequencing of her parents and fetus.@*RESULTS@#The proband was found to harbor compound heterozygous variants c.17_18insA (p.Tyr6Ter*) and c.4095_4096insA (p.Arg1366Lys fs*38) of the PCDH15 gene (NM_033056), which were respectively inherited from her father and mother. The same variants were not detected in 100 healthy controls. Based on the guidelines of the American Society of Medical Genetics and Genomics, both variants were predicted to be pathogenic (PVS1+PM2+PP4). By prenatal diagnosis, her fetus was found to carry the c.4095_4096insA variant. After birth, the child has passed neonatal hearing screening test, and no abnormal auditory and visual function was found after the first year.@*CONCLUSION@#The compound heterozygous variants c.17_18insA (p.Tyr6Ter*) and c.4095_4096insA (p.Arg1366Lys fs*38) of the PCDH15 gene probably underlay the Usher syndrome is this proband.

Analysis of CNTNAP1 gene variants in a Chinese pedigree affected with lethal congenital contracture syndrome type 7 / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a couple who had developed polyhydramnios during three pregnancies and given birth to two liveborns featuring limb contracture, dyspnea and neonatal death.@*METHODS@#Whole-exome sequencing (WES) was carried out on fetal tissue and peripheral blood samples from the couple. Suspected variants were verified by Sanger sequencing.@*RESULTS@#The fetus was found to harbor homozygous nonsense c.3718C>T (p.Arg1240Ter) variants of the CNTNAP1 gene, which were respectively inherited from its mother and father. The variant was unreported previously. According to the guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic (PVS1+PM2+PP4).@*CONCLUSION@#The novel homozygous nonsense variants of the CNTNAP1 gene probably underlay the lethal congenital contracture syndrome type 7 (LCCS7) in this pedigree. Above finding has enabled genetic counseling and prenatal diagnosis for the family.

Analysis of a Chinese pedigree affected with dyschromatosis symmetrica hereditaria due to a novel variant of ADAR gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with dyschromatosis symmetrica hereditaria (DSH).@*METHODS@#PCR and Sanger sequencing were carried out for the proband, and suspected variant was validated by Sanger sequencing in the pedigree.@*RESULTS@#The proband was found to harbor a novel variant of c.1352delA (p.N451Mfs*13) of the ADAR (NM_001111) gene. The same variant was found in her affected mother and sister, but not in her unaffected father, uncle, and 100 healthy individual.@*CONCLUSION@#The novel variant of the ADAR gene probably underlay the pathogenesis of DSH in this pedigree.

Identification and analysis of anovel variant of TRAPPC2 in a X-linked spondyloepiphyseal dysplasia tarda pedigree / 中华骨科杂志

Objective:To provide experimental evidence for genetic counseling and prenatal diagnosis by analyzing the clinical characteristics, screening and identification of the function of suspicious variants in a X-1inked spondyloepiphyseal dysplasia tarda (SEDT) family.Methods:The family members' medical history, general physical examination, femur, spine X-ray examination were collected. Peripheral blood samples of the family members were collected and DNA was extracted from these samples. Sequencing clinical whole exons of proband DNA by targeted gene high-throughput sequencing method, then analysis sequencing data. The suspicious mutation was confirmed in pedigree members by PCR and Sanger sequencing. Reverse transcription polymerase chain reaction (RT-PCR) experiments of total RNA from blood lymphocytes were performed. The amplification of exons 3 and 4 of the pathogenic gene were amplified and identified by agarose gel. The expression of the pathogenic gene was also detected.Results:Three affected males of the family were diagnosed with SEDT according to their clinical and radiological features. A nonsense mutation in the transport protein particle complex subunit 2 ( TRAPPC2) gene NM_001011658: c.91A>T (p.K31*) was found in the proband using whole exome sequencing. This variation was also detected in his cousin, but not in non-phenotypic members of the family. The RT-PCR result for amplification of exon 3 and 4 of peripheral blood lymphocytes was the same as those of normal controls, indicating that the mutation did not affect the splicing of transcripts. qPCR results showed that the transcriptional expression of TRAPPC2 in patients was significantly lower than that in family normal controls and normal people controls. Conclusion:Identification of the novel nonsense mutation (c.91A>T) in the SEDT family enables early patients screening, carrier detection, genetic counseling, prenatal diagnosis, and clinical prevention and treatment. The detailed genotype/phenotype descriptions contribute to the SEDT mutation spectrum. The study of the function of TRAPPC2 mutation will help to further elucidate the role of sedlin in cartilage.

Unexpected detection of Duchenne muscular dystrophy gene mutation by array comparative genomic hybridization in prenatal diagnosis: a retrospective analysis / 中华围产医学杂志

Objective:To explore the accuracy of array comparative genomic hybridization(aCGH) in the unexpected detection of Duchenne muscular dystrophy ( DMD) gene duplication/deletion in prenatal diagnosis. Methods:A retrospective analysis was performed on 31 cases with DMD gene duplication/deletion detected by aCGH among 5 025 prenatal diagnosis samples without family history of DMD in Henan Provincial People's Hospital from July 2018 to December 2019. The multiplex ligation-dependent probe amplification (MLPA) method was used to verify the above results. The American College of Medical Genetics and Genomics (ACMG) guideline was referred for pathogenicity analysis of the detected duplicates/deletions. Descriptive analysis was adopted in analysis. Results:The total unexpected DMD gene duplication/deletion rate was 0.62% (31/5 025), among which 25 cases were with microduplication/microdeletion ≤ 200 kb and six were >200 kb; there were 24 cases of deletion, seven cases of duplication; exon or intron duplication/deletion were accounted for 19 and 12 cases, respectively. According to the five classification standards of ACMG guideline, there were 17 cases with pathogenic variants and 14 cases with uncertain pathogenicity/likely benign variants. Of the 19 with exon mutations, 17 cases were DMD intragenic variants, and two cases involved variants in and outside DMD gene, which were verified by MLPA whose results were all positive. Conclusions:The duplication/deletion of exon region of DMD gene detected by aCGH technique is accurate and reliable, which plays an important role in the diagnosis of DMD. For these cases involved both internal and external regions of DMD gene, aCGH can identify the upstream and downstream breaking points of DMD gene, thus providing the basis for ACMG grading.

Research on prenatal genetic diagnosis of fetal renal cystic disease / 中华肾脏病杂志

Objective:To summarize the diagnosis features of the prenatal genetic diagnosis of fetal renal cystic disease and to explore the clinical feasibility and significance of prenatal genetic diagnosis of congenital cystic nephrosis.Methods:A total of 25 fetuses with congenital renal cystic disease were examined via invasive prenatal diagnosis in Henan Provincial People's Hospital from June 2017 to September 2019. Amniotic fluid samples were extracted by amniocentesis. Chromosomal microarray analysis (CMA) were performed in 17 cases. In addition to CMA, the other 8 cases were analyzed by G-band karyotype. Whole exome sequencing (WES) was performed in 6 cases which got normal results by CMA and karyotype, and highly suspected as hereditary disease.Results:Of the 25 fetuses assessed, 4 cases (16.0%) pathogenic copy number variation (pCNV) were found, including 2 cases of 17q12 deletion, 1 case of 10p15.1p14 deletion and 1 case of 4q21.28q22.1 deletion(including PKD2 gene). There were 8 cases without chromosome abnormality by karyotype analysis. Six clinical WES analysis found NPHS1 gene c.1440+1 G>A and c.925G > T mutations were related to Finnish type congenital nephrotic syndrome in 1 case, PKD1 gene c.6878C>T mutation was related to autosomal dominant polycystic kidney disease (ADPKD) in 1 case, and there was no definitive mutation in 4 cases. Conclusions:CMA and next generation sequencing are powerful tools for accurate diagnosis, treatment and genetic counseling of fetal congenital renal cystic diseases. For congenital cystic nephropathy, genetic detection is helpful to clarify the etiology, and provide more exactly informations for prognosis evaluation, treatment and family genetic counseling.

Genetic and phenotypic analysis of a case of epilepsy with developmental retardation caused by partial duplication of long arm of chromosome 19 / 中华实用儿科临床杂志

Objective:To investigate the genetic etiology of a child with epilepsy accompanied by motor retardation.Methods:A patient with epilepsy and motor retardation in Henan Provincial People′s Hospital in January 2020 and his parents′ peripheral blood 2 mL were collected.G-banded karyotyping and array-based comparative genomic hybridization (aCGH) were used to analyze the duplication / deletion of chromosome segments in child and her pa-rents.Results:The karyotype of the patient revealed 46, XX, and add(19)(p13.3→qter), whereas aCGH detected a 9.50 Mb duplication at 19q13.33q13.43[arr(hg19)(49593920_59092570)×3]. This region contains 471 genes.No abnormality was discovered in the karyotyping and aCGH analysis of the patient′s parents.The phenotypes of the patient conformed to the previously reported clinical characteristics of 19q13.3 duplication.Conclusions:The de novo 19q13.3 duplication is the cause of epilepsy and motor development retardation for the patient.Combined with aCGH, the traditional G banding is valuable to diagnose the patient with developmental delay.

Genetic analysis of a pedigree with atypical partial 4q trisomy / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with mental retardation.@*METHODS@#G-banded karyotyping analysis and single nucleotide polymorphism microarray (SNP array) were used to detect the genetic variants within the family, and the origin of the variants was analyzed using UPDtool Statistics software.@*RESULTS@#The patient, a 26-year-old female, was found to have a chromosomal karyotype of 46,XX,dup(4)(q28.2q31.3),and SNP array revealed a 25.71 Mb duplication at 4q28.2-q31.3. The duplication was inherited from her father, and her fetus was found to carry the same duplication.@*CONCLUSION@#The duplication of the patient probably underlay the mental retardation. The gender of the carrier and parental origin of the duplication might have led to the variation in their clinical phenotype.

A case of hyaline fibromatosis syndrome caused by compound heterozygous mutations in the ANTXR2 gene / 中华皮肤科杂志

A female patient aged 7 years and 5 months presented with multiple skin defects of the scalp, ears, hands and in the sacrococcygeal region, and multiple joint flexion contractures of the extremities for more than 7 years. Skin examination showed skin defects of the scalp, auricles, hands and in the sacrococcygeal region, gingival swelling, and multiple joint flexion contractures of the extremities. Genetic testing of the peripheral blood revealed 2 compound heterozygous mutations c.1073delC (A359Lfs*51) and c.1073dupC (A359Cfs*13) in the anthrax toxin receptor-2 ( ANTXR2) gene in the patient, which were inherited from her mother and father respectively. The patient was diagnosed with hyaline fibromatosis syndrome. Surgical treatment was rejected, and anti-inflammatory drugs, analgesics and other drugs were administered for symptomatic treatment. During follow-up of half a year, the child occasionally had mild diarrhea, and other symptoms did not progress markedly.

Clinical characteristics and pathogenic gene analysis in a large pedigree with multiple epiphyseal dysplasia / 中华骨科杂志

Objective To provide experimental evidence for genetic counseling and prenatal molecular diagnosis by analyzing the clinical characteristics and screening for pathogenic genes of a five-generation suspected multiple epiphyseal dysplasia (MED) family (17 patients).Methods The family members' medical history,general physical examination and hip joint X-ray examination were collected.Peripheral blood samples of the family members were collected and DNA were extracted from these samples.The exons of clinical genes from probands' DNA were sequenced by High throughput sequencing method.Next Gene software was used to compare and analyze the sequence and INGENUITY software was further used to annotate the mutations in order to find the pathogenic mutations in probands.The suspicious mutations were confirmed in pedigree members by PCR and Sanger sequencing.Results The family consisted of 5 generations and 38 members.Pedigree analysis was consistent with autosomal dominant inheritance.There were 17 patients in the family,and their clinical manifestations showed abnormal walking posture in childhood,pain in hip and knee joints,and typical pathological changes of epiphyseal dysplasia on X-ray.Cartilage oligomeric matrix protein (COMP) gene c.1153G ＞ A (p.Asp385Asn) missense heterozygous mutation was screened in proband,which was genotypically and phenotypically segregated in the pedigree.Conclusion A missense mutation of the comp gene has been identified in a pedigree affected with MED which was the first reported in a big family.Our result is conducive to the further diagnosis and treatment and also provides a molecular basisfor the future prenatal diagnosis.

Practice of standardized training of clinical medical genetics / 中华医学教育探索杂志

In 2014, the training of clinical medical genetics was included in the training sequence of resident standardized training in China. The standardized training of clinical geneticist in China started relatively late. As a whole, the training and qualification system of clinical hereditary physicians are still in the process of development and perfection. Based on "Rules for the training of department of medical genetics", basic medical genetics resident training system was established in Henan Provincial People's Hospital. Additionally, we took advantage of interactive online education platform, multiple disciplinary team, the analysis of positive case report, literature report and other teaching practices combined with the tutor system. After 4 years of exploration and practice, the program can quickly improve the residents' comprehensive ability, such as theoretical knowledge, professional literacy, clinical practice skills, and scientific research ability.

Clinical characteristics and pathogenic gene analysis in a large pedigree with multiple epiphyseal dysplasia / 中华骨科杂志

Objective@#To provide experimental evidence for genetic counseling and prenatal molecular diagnosis by analyzing the clinical characteristics and screening for pathogenic genes of a five-generation suspected multiple epiphyseal dysplasia (MED) family (17 patients).@*Methods@#The family members' medical history, general physical examination and hip joint X-ray examination were collected. Peripheral blood samples of the family members were collected and DNA were extracted from these samples. The exons of clinical genes from probands' DNA were sequenced by High throughput sequencing method. Next Gene software was used to compare and analyze the sequence and INGENUITY software was further used to annotate the mutations in order to find the pathogenic mutations in probands. The suspicious mutations were confirmed in pedigree members by PCR and Sanger sequencing.@*Results@#The family consisted of 5 generations and 38 members. Pedigree analysis was consistent with autosomal dominant inheritance. There were 17 patients in the family, and their clinical manifestations showed abnormal walking posture in childhood, pain in hip and knee joints, and typical pathological changes of epiphyseal dysplasia on X-ray. Cartilage oligomeric matrix protein (COMP) gene c.1153G>A (p.Asp385Asn) missense heterozygous mutation was screened in proband, which was genotypically and phenotypically segregated in the pedigree.@*Conclusion@#A missense mutation of the comp gene has been identified in a pedigree affected with MED which was the first reported in a big family. Our result is conducive to the further diagnosis and treatment and also provides a molecular basisfor the future prenatal diagnosis.

Genetic analysis of a child with atypical Williams-Beuren syndrome presenting as supravalvular aortic stenosis / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with supravalvular aortic stenosis.@*METHODS@#The child and his parents were subjected to conventional G-banding karyotyping, array comparative genomic hybridization (aCGH) and multiplex ligation-dependent probe amplification (MLPA) analysis.@*RESULTS@#No karyotypic abnormality was detected in the child and his parents. aCGH has identified a de novo 278 kb deletion encompassing the ELN gene in 7q11.23, which overlapped with the critical region of Williams-Beuren syndrome (WBS). MLPA has confirmed above findings.@*CONCLUSION@#The proband was diagnosed with atypical WBS. Deletion of the ELN gene may predispose to supravalvular aortic stenosis in the proband.

Identification of SPAST gene variant in a pedigree affected with hereditary spastic paraplegia type 4 / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a pedigree affected with hereditary spastic paraplegia type 4 (HSP4).@*METHODS@#Peripheral venous blood samples were taken from members of the four-generation pedigree and 50 healthy controls for the extraction of genomic DNA. Genes associated with peripheral neuropathy and hereditary spastic paraplegia were captured and subjected to targeted capture and next-generation sequencing. The results were confirmed by Sanger sequencing.@*RESULTS@#DNA sequencing suggested that the proband has carried a heterozygous c.1196C>G variant in exon 9 of the SPAST gene, which can cause substitution of serine by threonine at position 399 (p.Ser399Trp) and lead to change in the protein function. The same variant was also detected in other patients from the pedigree but not among unaffected individuals or the 50 healthy controls. Based on the ACMG 2015 guidelines, the variant was predicted to be possibly pathogenic.@*CONCLUSION@#The c.1196C>G variant of the SPAST gene probably underlay the HSP4 in this pedigree.

Genetic analysis of a patient with late infantile metachromatic leukodystrophy / 中华医学遗传学杂志

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.

Influence of uniparental disomy on the conclusion of paternity testing / 中华医学遗传学杂志

Objective@#To explore the influence of uniparental disomy (UPD) on bipartite and tripartite paternity testing.@*Methods@#Two cases of paternity testing were analyzed by multiplex amplification and capillary electrophoresis typing. Suspected UPD was verified by using single nucleotide polymorphism array (SNP array). Parental power index was calculated by using a bipartite or tripartite model.@*Results@#The two cases were found to harbor respectively three short tandem repeats on chromosome 2 and two short tandem repeats on chromosome 15. SNP array verified that both cases were of UPD. Case 1 had a parental power index of 122274987565.23 by a tripartite model, while case 2 had a parental power index of 13500.8463 by a bipartite model. Based on the technical specification, the conclusions supported a biological parent-child relationship in both cases.@*Conclusion@#UPD may lead to misjudgment of paternity testing. The possibility of UPD should be considered when certain loci which do not conform to Mendelian inheritance have aggregated to one chromosome.

Prenatal diagnosis of a fetus affected with Finnish type congenital nephrotic syndrome / 中华医学遗传学杂志

Objective@#To explore the genetic basis for a fetus suspected for congenital nephrotic syndrome of Finland (CNF).@*Methods@#Genomic DNA was extracted from peripheral and umbilical cord blood samples derived from both parents and the fetus. Potential variants were detected by using next-generation sequencing. Suspected variants were confirmed by Sanger sequencing.@*Results@#The fetus was found to carry compound heterozygous variants c. 1440+ 1G>A and c. 925G>T of the NPHS1 gene, which were respectively inherited from its mother and father.@*Conclusion@#Identification of the compound heterozygous NPHS1 variants has enabled diagnosis of CNF in the fetus and genetic counseling for the affected family.