Microcephaly-seizures-development delay syndrome in a pedigree: genetic analysis and literature review / 中华围产医学杂志

Objective:To analyze the phenotypes and genetic etiology of microcephaly- seizures-development delay (MCSZ) syndrome.Methods:The patient was diagnosed with MCSZ syndrome in June 2018 at Shenzhen Maternity and Child Healthcare Hospital. She was the couple's first child, and the mother conceived a second child in 2020. The clinical data of the proband were retrospectively analyzed, and the bioinformatics analysis and whole-exome sequencing (WES) were performed on the proband and her parents to identify the pathogenic variants, which were further validated using Sanger sequencing. The prenatal genetic diagnosis of the second fetus was performed following the molecular diagnosis of the proband was confirmed. The clinical manifestations and pathogenesis of MCSZ syndrome were summarized by reviewing related literature.Results:(1) Case report: The patient, an eight-month-old girl, was admitted to our hospital due to microcephaly and repeated seizures. Another clinical characteristic was mental retardation. Auditory evoked potential detected moderate impairment of the left auditory nerve pathway. WES showed a compound heterozygous variation in the PNKP gene of the proband. Moreover, the pathogenic variation, c.199-10_203delinsTCTGAGGGGT, was inherited from the father, and the likely pathogenic variation, c.1505C>T(p.P502>L), was inherited from the mother, which was both de novo mutations. The compound heterozygous variation in the PNKP gene was considered genetic etiology based on the genetic testing and clinical features. Prenatal diagnosis showed that the second fetus did not inherit the PNKP gene variants from the parents and the couples chose to continue the pregnancy. A girl was born, and her psychomotor development and occipitofrontal size circumference were normal at 13 months old. (2) Literature review: 39 MCSZ syndrome cases were retrieved, including the present case and 38 cases from 12 relevant literature. The clinical characteristics were microcephaly (91.7%, 33/36), seizures (88.2%, 30/34), development delay (96.4%, 27/28), hyperactivity (25.6%, 9/39), gastroesophageal reflux (10.3%, 4/39), and hearing loss (7.7%, 3/39). Most patients' first onset of epilepsy was in infancy (96.3%, 26/27). Cranial MRI examination showed brain dysplasia in 31 cases (91.2%, 31/34). Conclusions:When the fetal head circumference is smaller than normal and is progressively reduced combined with postnatal microcephaly, epilepsy, developmental retardation, hyperactivity disorder, gastroesophageal reflux, and hearing loss, MCSZ syndrome should be considered. The prognosis varies widely, and genetic testing facilitates the early diagnosis and genetic counseling of MCSZ syndrome.

Prenatal diagnosis of Aicardi-Goutières syndrome type 3: report of two pedigrees / 中华围产医学杂志

Two pedigrees are reported here including two siblings and a boy who were diagnosed with Aicardi-Goutières syndrome type 3 (AGS3) caused by compound heterozygous variation of RNASEH2C gene. Prenatal gene diagnosis was performed when their mothers were pregnant again. All three cases presented with epilepsy, microcephaly, muscular hypertonia and severe language, motor and mental retardation. In pedigree 1, genetic analysis showed compound heterozygous variants of c.194G>A (p.Gly65Asp) and c.434G>T (p.Arg145Leu) in the RNASEH2C gene of proband 1 and her younger brother, which were inherited from their mother and father respectively. While in pedigree 2, c.194G>A(p.Gly65Asp) and c.227C>T(p.Pro76Leu) compound heterozygous variants in the RNASEH2C gene were found in proband 2, which were inherited from his father and mother, respectively. Diagnosis of AGS3 was confirmed in these three cases based on their medical history and the testing results. The mothers from the two families underwent prenatal diagnosis in their subsequent pregnancy, and the variation only inherited from the mothers was detected, suggesting that the two fetuses are carriers. Both families chose to continue the pregnancy and delivered at full-term. No growth or development abnormalities were reported in the children during a one-year follow-up.

Clinical characterization and genetic analysis of a newborn with chromosome 8q21.11 deletion syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic etiology for a newborn with corneal opacity.@*METHODS@#The neonate and her parents were subjected to routine G-banding chromosomal karyotyping analysis. Copy number variation (CNV) was analyzed with low-coverage whole-genome sequencing (WGS) and single nucleotide polymorphism microarray (SNP array).@*RESULTS@#No karyotypic abnormality was found in the newborn and her parents. Low-coverage WGS has identified a de novo 5.5 Mb microdeletion at chromosome 8q21.11-q21.13 in the neonate, which encompassed the ZFHX4 and PEX2 genes. The result was confirmed by SNP array-based CNV analysis.@*CONCLUSION@#The newborn was diagnosed with chromosome 8q21.11 deletion syndrome. ZFHX4 may be one of the key genes underlying this syndrome.

Genetic analysis of a family with congenital heart defects caused by chromosome 8p23.1 deletion / 中华医学遗传学杂志

Objective@#To explore the genetic basis for a family affected with congenital heart defects.@*Methods@#G-banding karyotyping, chromosomal microarray analysis (CMA) and multiplex ligation-dependent probe amplification (MLPA) were carried out to detect copy number variants in a patient with left ventricular noncompaction (LVNC) and his fetus.@*Results@#G-banding karyotyping showed the patient was 45, XY, rob(15; 21)(q10; q10)[36]/46, XY[64], while the fetus had an normal karyotype. CMA revealed that both had arr[hg19]8p23.1(11 232 919-11 935 465)×1. MLPA showed both had deletion of all exons of the GATA4 gene.@*Conclusion@#The LVNC of the patient and the ventricular septal defect(VSD) of his fetus may result from the same 8p23.1 deletion, for which GATA4 is probably the key gene.

Genetic analysis of a family with congenital heart defects caused by chromosome 8p23.1 deletion / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a family affected with congenital heart defects.@*METHODS@#G-banding karyotyping, chromosomal microarray analysis (CMA) and multiplex ligation-dependent probe amplification (MLPA) were carried out to detect copy number variants in a patient with left ventricular noncompaction (LVNC) and his fetus.@*RESULTS@#G-banding karyotyping showed the patient was 45,XY,rob(15;21)(q10;q10)[36]/46,XY[64], while the fetus had an normal karyotype. CMA revealed that both had arr[hg19]8p23.1(11 232 919-11 935 465)×1. MLPA showed both had deletion of all exons of the GATA4 gene.@*CONCLUSION@#The LVNC of the patient and the ventricular septal defect(VSD) of his fetus may result from the same 8p23.1 deletion, for which GATA4 is probably the key gene.

Genetic diagnosis for fetal Bardet-Biedl syndrome caused by BBS7 gene mutations: report of two cases / 中华围产医学杂志

Objective:To summarize the genetic diagnosis of two fetuses with clinically suspected Bardet-Biedl syndrome (BBS) and to provide information for genetic counseling and prenatal diagnosis of BBS.Methods:Case one had prenatal care on October 2018 in Shenzhen Maternity and Child Healthcare Hospital and was clinically suspected of fetal BBS as bilateral renal parenchyma echo enhancement as well as polydactyly (six toes on each foot) were shown on ultrasonic examination at 18 +1 gestational weeks. Case two was another suspected fetal BBS for enlarged kidneys with echo enhancement as well as polydactyly (six fingers and toes on each hand and foot) on ultrasonic examination at 26 +4 gestational weeks on August 2016 and the parent requested for termination. Parents of both cases requested for genetic analysis. Amniotic fluid sample was obtained in case one at 19 +6 weeks through amniocentesis, and umbilical cord specimen of case two and peripheral blood samples of the parents were collected. Genetic analysis of the fetuses and their parents was performed using exon capture and next-generation sequencing and the results were validated using Sanger sequencing. Results:Case one carried paternally inherited c.718G>A (p.Gly240Ser) (possible pathogenic) mutation and maternally inherited c.497C>A(p.Ala166Asp) (possible pathogenic) mutation in BBS7 gene. While one paternally inherited mutation c.1002delT(p.N335Ifs*47) (pathogenic) and one maternally inherited heterozygous mutation c.728G>A (p.Cys243Tyr) (possible pathogenic) were identified in BBS7 gene of case two. The three unreported missense mutations were predicted to be harmful by bioinformatics software and the mutation sites were conservative after comparing with multiple species-based protein sequences. Conclusions:Enlarged kidneys with echo enhancement and polydactyly may indicated a BBS fetus caused by BBS7 gene mutation. Whole exome sequencing could provide relevant information for prenatal diagnosis and genetic counseling in these cases.

Prenatal diagnosis of Jacobsen syndrome: analysis of four cases / 中华围产医学杂志

Objective To investiget the value of chromosome microarray analysis (CMA) in prenatal diagnosis of Jacobsen syndrome.Methods Among all gravidas who received karyotype analysis and CMA because of fetal congenital cardiac abnormalities in Shenzhen Maternity & Child Healthcare Hospital Affiliated to Southern Medical University from 2014 to 2016,four were diagnosed with fetal Jacobsen syndrome and enrolled in this study.Three amniotic fluid and one fetal tissue samples were collected.Peripheral blood specimens were collected from parents of these fetuses.Amniotic fluid samples and peripheral blood specimens were analyzed by karyotype analysis.CMA was performed to analyze amniotic fluid and fetal tissue samples.Multiplex ligation-dependent probe amplification was used to verify abnormal results revealed by CMA.Results (1) Prenatal ultrasound results:Fetus 1 was complicated with monocardian and transposition of the great arteries,fetus 2 with single umbilical artery and double superior vena cava,fetus 3 with severe constricted aorta and ventricular septal defect and fetus 4 with hypoplastic left heart syndrome and presented with a nuchal translucency of 0.27 cm.(2) Karyotyping results of the three amniotic fluid samples were 46,XY,del(11)(q23.3),46,XX,del(11)(q23.3) and 46,XX,del(11)(q23),respectively.(3) CMA results of the four fetuses were arr[GRCh37]11q24.1q25(121 872 273-134 934 196)× 1(13.062 Mb),arr[GRCh37]11q24.1q25(121 325 694-134 937 416)× 1 (13.611 Mb),arr[GRCh37]11q23.3q25(118 977 029-134 937 416)× 1 (15.960 Mb) and arr[GRCh37]11q24.1q24.3(123 144 040-130 308 335)× 1(7.164 Mb),respectively.All chromosomal aberrations in these fetuses were de novo as no abnormalities were found in their parents through karyotyping.All abnormal CMA results were confirmed by multiplex ligation-dependent probe amplification.Conclusions Jacobsen syndrome should be considered when fetuses are diagnosed with congenital cardiac abnormalities by ultrasound.CMA can be used to accurately diagnose Jacobsen syndrome and determine the region and size of chromosome deletion.

Genetic analysis and prenatal diagnosis for ten families affected with tuberous sclerosis complex / 中华医学遗传学杂志

OBJECTIVE To provide prenatal diagnosis for families affected with tuberous sclerosis complex and explore the correlation between phenotype and genotype. METHODS For probands from 10 families, all exons and splicing regions of the TSC1 and TSC2 genes were analyzed with high throughput DNA sequencing. Suspected mutations were verified by Sanger sequencing. RESULTS All probands were found to have mutations, which included 1 case with TSC1 mutation and 9 cases with TSC2 mutations (missense mutations in 6, nonsense mutations in 2, and frameshifting mutation in 1 case). Prenatal diagnosis was provided for 9 cases, and 1 fetus was found to carry a mutation. Genetic analysis has identified a novel pathogenic mutation (TSC2 c.2415-2416 ins GT). CONCLUSION Identification of pathological mutations for tuberous sclerosis complex can facilitate genetic counseling and prenatal diagnosis for the affected families.

Chromosome abnormality analysis of 7 036 chorionic villi inspontaneous miscarriage cases by multiplex ligation-dependent probe amplification / 中华检验医学杂志

Objective To investigate chromosomal aneuploidy of chorionic villior tissue from embryo arrestor spontaneous miscarriage by the method of multiplex ligation-dependent probe amplification(MLPA), and to provide genetic etiology data for recurrent spontaneous abortion(RSA) and embryo arrest.Methods The clinical retrospective analysis was used during November 2013 to October 2016 in Shenzhen Maternity and Child Healthcare Hospital.The genomic DNA of 7 036 chorionic villi or tissue samples from embryo arrestor pregnancy loss were extracted by resin and Proteinase K, following detected by multiplex ligation-dependent probe amplification, and then analyzed by descriptive and frequency statistic using SPSS17.0 software.Results Totally 2 984 samples (42.41%) with chromosomal aneuploidy were detected, of which, the top five were trisomy 16(826)11.74%, monosomy X (Turner,401)5.70%, trisomy 22(247)3.51%, trisomy 13(149)2.12% and trisomy 21(144)2.05%.Aneuploidy 19 or 17 were rare,just 1 and 3 cases respectively.The aneuploidy of chromosome 1 was not discovered yet.There were 161 samples (2.28%) for segmental deletion and/or duplication cases.Besides of the monosomy X(Turner,401), monsomy 21 was also high frequency(17,0.24%).In addition, 56 samples(0.80%)were double trisomic,while 2 samples(0.03%)were tris-trisomy.Thirteen samples(0.18%)were heterosome trisomy,and five samples(0.07%)were Turner combined trisomy.Fifteen samples(0.21%) were unbalanced translocation of the arm,while 20 samples(0.28%) were nonhomologous chromosome translocation.Conclusions Trisome and monosome were the majority of chromosome abnormality (above 90%), as well as the main cause of spontaneous miscarriage.Meanwhile the chromosome aneuploidy (including segment deletion or duplication) could be screened by MLPA quickly, thoroughly and efficiently, further more discover the carrier of balanced translocation in couples and provide valuable genetic information for next pregnancy.

Analysis of a mistake occurring during prenatal diagnosis of two couples respectively carrying CD41-42 (-TCTT) and CD43(G>T) mutations of the beta hemoglobin gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To provide prenatal diagnosis for two couples who respectively carried heterozygous CD41-42 (-TCTT) and CD43 (G>T) mutations of the beta hemoglobin gene.</p><p><b>METHODS</b>The mutations were simultaneously detected with reverse dot blot (two diagnostic kits), multi-color melting curve analysis and sequencing analysis.</p><p><b>RESULTS</b>The fetus of family 1 was shown to be heterozygous for CD43 (G>T) by the three methods, while the fetus of family 2 was shown to be double heterozygous for CD41-42 (-TCTT) and CD43 (G>T) by multi-color melting curve analysis and sequencing analysis. The two diagnostic kits yielded different results by reverse dot blot, one as double heterozygous for CD41-42 (-TCTT) and CD43 (G>T), and another as homozygous for CD41-42 (-TCTT).</p><p><b>CONCLUSION</b>For prenatal diagnosis of couples carrying mutations of beta hemoglobin gene such as CD41-42 (-TCTT) and CD43 (G>T), other methods such as Sanger sequencing should be used in order to avoid misdiagnosis.</p>

Non-invasive prenatal test in 2 949 intermediate risk women after traditional Down syndrome screening / 天津医药

Objective To explore the value of non-invasive prenatal test (NIPT) in pregnant women with intermediate risk after traditional Down syndrome screening. Methods From March 1 2015 to March 31 2016, a total of 2 949 pregnant women with intermediate risk after traditional Down syndrome screening who received NIPT as the second-line screening method at Shenzhen Maternity and Child Healthcare Hospital after informed consent were recruited for this study. Retrospective data analysis including the results of traditional Down syndrome screening, ultrasound, NIPT and invasive amniocentesis to fetal karyotype analysis were conducted, and pregnant outcomes were followed up. Results NIPT results were all obtained in 2 949 pregnant women with intermediate risk after traditional Down syndrome screening. Of 25 NIPT-positive cases, 24 cases received invasive amniocentesis to fetal karyotype analysis. Thirteen cases were confirmed with fetal chromosomal abnormalities including 5 cases of trisomy 21, 2 cases of trisomy 13, 4 cases of sex chromosomal abnormalities and 2 cases of other chromosomal abnormalities. In addition, 1 NIPT-positive case refused prenatal diagnosis was confirmed normal result after birth. The postnatal follow-up in NIPT-negative women did not find any newborn with chromosomal abnormality. The incidence of fetal chromosomal abnormalities in women with intermediate risk was 0.44% (13/2 949). Conclusion NIPT can be used as second-line screening method in pregnant women with intermediate risk after Down syndrome screening, which could lead to the prenatal detection of a higher proportion of fetal chromosomal abnormalities and a lower invasive-testing rate.

Combined G-banded karyotyping and multiplex ligation-dependent probe amplification for the detection of chromosomal abnormalities in fetuses with congenital heart defects / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the value of G-banded karyotyping in combination with multiplex ligation-dependent probe amplification (MLPA) as a tool for the detection of chromosomal abnormalities in fetuses with congenital heart defects.</p><p><b>METHODS</b>The combined method was used to analyze 104 fetuses with heart malformations identified by ultrasonography. Abnormal findings were confirmed with chromosomal microarray analysis (CMA).</p><p><b>RESULTS</b>Nineteen (18%) fetuses were found to harbor chromosomal aberrations by G-banded karyotyping and MLPA. For 93 cases, CMA has detected abnormalities in 14 cases including 10 pathogenic copy number variations (CNVs) and 4 CNVs of uncertain significance (VOUS). MLPA was able to detect all of the pathogenic CNVs and 1 VOUS CNV.</p><p><b>CONCLUSION</b>Combined use of G-banded karyotyping and MLPA is a rapid, low-cost and effective method to detect chromosomal abnormalities in fetuses with various heart malformations.</p>

The application of multicolor probe melting curve analysis for the prenatal diagnosis ofβthalassemia / 中华检验医学杂志

Objective To establish a method of multicolor melting curve analysis for the prenatal diagnosis ofβthalassemia.Methods Methodology establishment.A total of 95 cases, including 9 fetal villi samples(10-13 weeks)and 86 amniotic fluid samples(18-24 weeks)were collected by Center for Prenatal Diagnosis of Shenzhen Maternity and Child Healthcare Hospital between January 2014 and December 2014.A double-blind test was done to detect the mutations of beta globin gene by means of reverse dot ( RDB) blot and multicolor melting curve analysis ( MMCA).The consistency of the two methods is compared.Results The results of 93 cases detected by MMCA and RDB are completely consistent.The results of the 2 cases detected by MMCA after correction are the same as the results detected by RDB.Finally, the coincidence rate of the result was 100%.Conclusion MMCA can be applied to the prenatal diagnosis ofβthalassemia as an effective supplement to RDB.

Association of FOXE1 gene polymorphism with idiopathic premature ovarian failure / 中华妇产科杂志

Objective To assess the influence of length of the alanine tract of forkhead box E1 (FOXE1) gene on genetic susceptibility to idiopathic premature ovarian failure (POF). Methods Totally 110 patients with idiopathic POF were recruited between February 2009 and December 2012 at the Affiliated Shenzhen City Maternity and Child Healthcare Hospital of Southern Medical University. Controls (n=110) were individuals with normal menstrual cycles, normal FSH concentrations. The polyalanine tract and flanking sequence of FOXE1 were screened using the multiplex ligation-dependent probe amplification (MLPA) technique and direct sequence technique. Results The most frequent of FOXE1 polyalanine stretch length was 14 residues in both groups. The length of FOXE1 polyalanine reported in this study varied from 12 to 16 alanines, and three variants of FOXE1-polyalanine length, containing 12, 14, or 16 alanine residues, and 5 different genotypes were identified. The most common genotypes were 14/14 homozygote, occurring with the frequency of 81.8% (90/110) in the POF group, while 96.4% (106/110) in control subjects, respectively. The incidence of 14/14 genotypes of FOXE1-polyalanine was significantly lower in patients with POF (χ2=119.730, P=0.001) in comparison to the controls. There were significantly higher frequencies of the 16/16 genotypes in cases with POF [10.0% (11/110) versus 0; χ2=3.403, P=0.001], as compared with the controls. The FOXE1 14 alanine allele was significantly less common in the POF patient group than the controls [84.5% (186/220) versus 98.2% (216/220); χ2=25.923, P=0.001]. The FOXE1 16 alanine allele was significantly more common in the POF patient group than the controls [12.7% (28/220) versus 1.8% (4/220); χ2=19.412, P=0.001]. Conclusions The polymorphism of the polyalanine tract of FOXE1 gene have a certain relevance for the genetic aetiology of idiopathic POF.

Clinical and genetic analysis for a Joubert syndrome family with CC2D2A gene mutations / 中华儿科杂志

<p><b>OBJECTIVE</b>To confirm the genetic diagnosis for providing services for genetic counseling and prenatal diagnosis, we analyzed the clinical and genetic data of a pedigree which is clinically diagnosed as Joubert syndrome.</p><p><b>METHOD</b>A Joubert syndrome pedigree was enrolled as subject of this study from our hospital's outpatients in 2013. Following the medical history collection of the proband and the suffering fetus, target sequence capture and the next-generation sequencing technology were used for the proband and the suffering fetus to find the causative genes and sanger sequencing for the members of the pedigree to check and verify if the inherited mutations are in accordance with the Mendelian inheritance. Combining the clinical symptoms and signs with the total testing results, we analyzed the Joubert syndrome pedigree clinically and genetically.</p><p><b>RESULT</b>The proband showed abnormal respiratory patterns (neonatal tachypnea) and hypertonia without abnormal eye movements, and reflected the molar tooth sign on the magnetic resonance imaging. And afterwards the patient developed hypotonia, ataxia, growth and intellectual disability accompanied by congenital blepharoptosis. There were no any symptoms and signs of liver, kidney and eyesight abnormalities so far. The affected fetus showed hydrocephalus by the auxiliary examination during the second trimesters of pregnancy without any appearance deformities. Both the proband and the affected fetus carried a missense mutation of CC2D2A gene c.2999A > T (p.Glu1000Val) from their father and carried the deletion of exon 20-21 on the same gene. Both variations were confirmed to be the Mendelian genetic compound heterozygous pattern. Whereas, the missense mutations c.2999A > T (p.Glu1000Val) on the CC2D2A gene have been proved to be inherited from the proband's father and the proband as well as the affected fetus. However, the proband's mother was normal at this locus of CC2D2A gene. The missense mutations c.2999A >T (p.Glu1000Val) have been confirmed to accord with Mendelian inheritance.</p><p><b>CONCLUSION</b>The Joubert syndrome patient may show hypertonia in the early postnatal days as a result of hydrocephalus during the second and third trimesters of pregnancy besides manifesting hypotonia, ataxia, growth and intellectual disability markedly with age accompanied by the congenital blepharoptosis and revealing the molar tooth sign on the magnetic resonance imaging, considering the medical history and the whole testing results, the compound heterozygous mutations of c.2999A > T (p.Glu1000Val) and deletion of exon 20-21 of CC2D2A gene in the pedigree may be the causal gene mutations.</p>

Genetic and prenatal diagnosis for a Chinese family with primary carnitine deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify potential mutation of SLC22A5 gene in a 5-month-old boy affected with primary carnitine deficiency and provide genetic counseling and prenatal diagnosis for the members of his family.</p><p><b>METHODS</b>DNA was extracted from peripheral blood samples derived from the proband, his parents and elder sister, as well as amniotic fluid from his pregnant mother. All of the 10 exons of the SLC22A5 gene were amplified by PCR and subjected to Sanger sequencing. The amniotic fluid sample was also subjected to G-banded karyotyping and multiplex ligation-dependent probe amplification (MLPA).</p><p><b>RESULTS</b>A homozygous mutation c.760C>T (p.R254X) of the SLC22A5 gene was detected in the proband. Heterozygous mutation c.760C>T (p.R254X) was also found in other family members including the fetus. The karyotyping and chromosomal microdeletion testing for the amniotic fluid sample were both normal.</p><p><b>CONCLUSION</b>The newly identified homozygous nonsense c.760C>T (p.R254X) mutation of the SLC22A5 gene probably underlies the primary carnitine deficiency of the proband. Genetic counseling and prenatal diagnosis have been provided for this family.</p>

Application of multiplex ligation-dependent probe amplification technique in prenatal diagnosis of α-thalassemia / 中华医学遗传学杂志

OBJECTIVE To assess the application value of multiplex ligation-dependent probe amplification (MLPA) for the detection of gene deletion and prenatal diagnosis of α-thalassemia. METHODS MLPA was applied for 2 cases with α-thalassemia phenotype by whole blood cell counting and hemoglobin component detection but were ruled out by regular molecular diagnosis. Potential gene deletions and point mutations of α-thalassemia gene were detected with regular Gap-polymerase chain reaction (Gap-PCR) and reverse dot blotting (RDB) in 89 cases where one or both partners were carriers of α-thalassemia mutations. Meanwhile, MLPA was used for detecting α-globin gene deletion among the 89 samples. RESULTS For the 2 cases with α-thalassemia phenotype, no α globin gene deletion was detected by MLPA, but were subsequently confirmed as iron-deficiency anemia. The results of MLPA and Gap-PCR detection for the 88 cases were consistent, except for 1 fetal sample (chorionic villi) which could not be diagnosed by Gap-PCR and was confirmed to be - SEA/αα by MLPA. CONCLUSION MLPA can be applied to prenatal diagnosis of α-thalassemia as an effective supplement to Gap-PCR to reduce both misdiagnosis and missed diagnosis and improve the accuracy of prenatal diagnosis.

Genetic analysis and prenatal diagnosis of two Chinese families with split hand foot malformation / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify genomic aberrations underlying pathogenesis of split hand foot malformation (SHFM) in two Chinese families, and to provide genetic counseling and prenatal diagnosis for them.</p><p><b>METHODS</b>Two sets of peripheral blood and amniotic fluid samples were collected from the patients. One was processed with routine culture and karyotype analysis. For another set, DNA was extracted and analyzed with array-based comparative genomic hybridization (array-CGH).</p><p><b>RESULTS</b>Karyotype analysis of peripheral blood samples for both probands was normal. Karyotype analysis of the amniotic fluid from family 1 has found no abnormality. However, analysis of amniotic fluid samples from the second family showed del(7)(q21q22.1). By array-CGH analysis, both blood and amniotic fluid samples from the first family showed a 662.3 kb dup(10q24.31q24.32). Array-CGH analysis of the blood sample from the second family was normal, whilst analysis of amniotic fluid sample revealed a 19.97 Mb del(7q11.23q21.3).</p><p><b>CONCLUSION</b>Array-CGH features high resolution, high accuracy and rapid diagnosis for unbalanced chromosomal aberration. The dup(10q24.31q24.32) and 19.97 Mb del(7q11.23q21.3) have been the cause of SHFM in the two families. Genetic counseling and prenatal diagnosis have been provided for both families in order to prevent this birth defect.</p>

Genetic analysis for a family with Cockayne syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify potential mutations among three sisters from a Chinese family suspected with Cockayne syndrome for growth and psychomotor retardation, and to offer genetic counseling and prenatal diagnosis for the family.</p><p><b>METHODS</b>G-banded karyotyping, microarray comparative genomic hybridization (CM-CGH), whole genome exon high-throughput sequencing and Sanger sequencing were employed to identify potential genetic variations for the three patients and their parents.</p><p><b>RESULTS</b>Whole exome sequencing has identified two novel missense mutations, i.e., c.1595A>G (p.Asp532Gly) and c.1607T>G (p.Leu536Trp), in exon 7 of excision repair cross-complementing rodent repair deficiency, complementation group 6 (ERCC6) gene. Sanger sequencing confirmed that all of the three sisters have inherited one of the mutations (c.1607T>G) from their father and another (c.1595A>G) from their mother.</p><p><b>CONCLUSION</b>Three sisters have all been identified as double heterozygote for mutations c.1607T>G and c.1595A>G and were diagnosed with Cockayne syndrome.</p>

A novel mutation in GCH1 gene causes dopa-responsive dystonia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify potential mutation of the GCH1 gene in a Chinese family affected with dopa-responsive dystonia.</p><p><b>METHODS</b>Genomic DNA of patients was extracted from peripheral blood samples. The 6 exons of the GCH1 gene and at least 100 bp of flanking intronic sequences were amplified with PCR. Potential mutations were screened by direct sequencing. Identified mutation was verified with denaturing high performance liquid chromatography (DHPLC) in 100 healthy controls.</p><p><b>RESULTS</b>All patients were found to be heterozygous for a novel c.597delT (p.Ala200LeufsX5) deletion in the exon 5 of the GCH1 gene. The deletion of T has resulted in formation of a shorter (203 amino acids) truncated non-functional guanosine triphosphate cyclohydrolase I. The same mutation was not found in the 100 controls.</p><p><b>CONCLUSION</b>A novel GCH1 gene frameshifing mutation probably underlies the dopa-responsive dystonia in this Chinese family.</p>