A de novo PAK1 likely pathogenic variant and a de novo terminal 1q microdeletion in a Chinese girl with global developmental delay, severe intellectual disability, and seizures.

BACKGROUND: Pathogenic PAK1 variants were described to be causative of neurodevelopmental disorder with macrocephaly, seizures, and speech delay. Herein, we present a de novo PAK1 variant combine with a de novo terminal 1q microdeletion in a Chinese pediatric patient, aiming to provide more insights into the underlying genotype-phenotype relationship. METHODS: Enrolled in this study was a 6-year-old girl with clinical features of global developmental delay, severe intellectual disability, speech delay, and seizures from Quanzhou region of China. Karyotype and chromosomal microarray analysis (CMA) were performed to detect chromosome abnormalities in this family. Whole exome sequencing (WES) was performed to investigate additional genetic variants in this family. RESULTS: No chromosomal abnormalities were elicited from the entire family by karyotype analysis. Further familial CMA results revealed that the patient had a de novo 2.7-Mb microdeletion (arr[GRCh37] 1q44(246,454,321_249,224,684) × 1]) in 1q44 region, which contains 14 OMIM genes, but did not overlap the reported smallest region of overlap (SRO) responsible for the clinical features in 1q43q44 deletion syndrome. In addition, WES result demonstrated a de novo NM_002576: c.251C > G (p.T84R) variant in PAK1 gene in the patient, which was interpreted as a likely pathogenic variant. CONCLUSION: In this study, we identify a novel PAK1 variant associated with a terminal 1q microdeletion in a patient with neurodevelopmental disorder. In addition, we believe that the main clinical features may ascribe to the pathogenic variant in PAK1 gene in the patient.

A First Clinical and Molecular Study of Rare IVS-II-806 (G > C) (HBB:c.316-45G > C) Variant in the ß-globin Gene: A Possibly Benign Variant.

Introduction: ß-thalassemia is a common genetic disease affecting a single gene, disease with a high incidence in South China. We hereby, aim to provide the clinical and hematological features of a rare ß-globin gene variant in the Chinese population. Methods: Ten subjects from three unrelated Chinese families were enrolled in this study. Hematological analysis and thalassemia gene testing were preformed to screen for common α and ß-thalassemia variants. Gap-polymerase chain reaction (Gap-PCR) and DNA sequencing were utilized to examine the rare or novel thalassemia variants. Results: Six cases were identified carrying the rare IVS-II-806 (G > C) (HBB:c.316-45G > C) variant in the ß-globin gene. The proband in family 1 carry three rare ß-globin gene mutations including CD39 (C > T), IVS-II-81 (C > T) and IVS-II-806 (G > C) combined with a --SEA/αα deletion, exhibiting the ß-thalassemia trait. Further pedigree investigation indicated that the genotype of the proband in family 1 was --SEA/αα, ßCD39 (C>T), IVS-II-81(C>T)/ßIVS-II-806(G>C). Meanwhile, the twin girls in family 1 carrying the IVS-II-806 (G > C) mutation demonstrated a normal hematological phenotype. In family 2, the proband and his sister carry the IVS-II-806 (G > C) mutation, eliciting high levels of Hb A2 and slightly low levels of MCV and MCH. Moreover, the proband in family 3 carrying the same mutation exhibited a slightly low MCV level as well. Conclusions: In this study, clinical and hematological analysis of the IVS-II-806 (G > C) mutation was first conducted within the Chinese population, with results indicating that it may be a benign variant.

Third-Generation Sequencing as a New Comprehensive Technology for Identifying Rare α- and ß-Globin Gene Variants in Thalassemia Alleles in the Chinese Population.

CONTEXT.­: Identification of rare thalassemia variants requires a combination of multiple diagnostic technologies. OBJECTIVE.­: To investigate a new approach of comprehensive analysis of thalassemia alleles based on third-generation sequencing (TGS) for identification of α- and ß-globin gene variants. DESIGN.­: Enrolled in this study were 70 suspected carriers of rare thalassemia variants. Routine gap-polymerase chain reaction and DNA sequencing were used to detect rare thalassemia variants, and TGS technology was performed to identify α- and ß-globin gene variants. RESULTS.­: Twenty-three cases that carried rare variants in α- and ß-globin genes were identified by the routine detection methods. TGS technology yielded a 7.14% (5 of 70) increment of rare α- and ß-globin gene variants as compared with the routine methods. Among them, the rare deletional genotype of -THAI was the most common variant. In addition, rare variants of CD15 (G>A) (HBA2:c.46G>A), CD117/118(+TCA) (HBA1:c.354_355insTCA), and ß-thalassemia 3.5-kilobase gene deletion were first identified in Fujian Province, China; to the best of our knowledge, this is the second report in the Chinese population. Moreover, HBA1:c.-24C>G, IVS-II-55 (G>T) (HBA1:c.300+55G>T) and hemoglobin (Hb) Maranon (HBA2:c.94A>G) were first identified in the Chinese population. We also identified rare Hb variants of HbC, HbG-Honolulu, Hb Miyashiro, and HbG-Coushatta in this study. CONCLUSIONS.­: TGS technology can effectively and accurately detect deletional and nondeletional thalassemia variants simultaneously in one experiment. Our study also demonstrated the application value of TGS-based comprehensive analysis of thalassemia alleles in the detection of rare thalassemia gene variants.

Etiological identification of recurrent male fatality due to a novel NSDHL gene mutation using trio whole-exome sequencing: A rare case report and literature review.

BACKGROUND: Congenital hemidysplasia with ichthyosiform nevus and limb defects (CHILD) syndrome is a rare X-linked dominant, lethal male disorder caused by mutations to the NSDHL (NAD(P)H steroid dehydrogenase-like protein) gene. It primarily exhibits strictly unilateral congenital hemidysplasia with ichthyosiform erythroderma and ipsilateral limb defects in female individuals. METHODS: A Chinese couple suffering from recurrent spontaneous abortion in male fetuses was enrolled in this study. Chromosomal microarray analysis and whole-exome sequencing were performed for genetic etiological diagnosis. RESULTS: A 33-year-old pregnant woman with recurrent spontaneous abortion was experiencing her third pregnancy with a male embryo. In this pregnancy, a miscarriage occurred at a gestational age of 10+6  weeks with no copy number variants. However, a novel mutation c.790-6C>T in the NSDHL gene was observed in the fetus through whole-exome sequencing (WES). Parental verification indicated that the NSDHL gene variant was inherited from the mother. Additionally, the variant in the NSDHL gene was absent in her subsequent pregnancy with a female fetus. CONCLUSION: In this study, we detected c.790-6C>T, a novel variant in the NSDHL gene that results in recurrent miscarriage in males. Our study may broaden the scope of research on the NSDHL gene in CHILD syndrome and strengthens the application value of WES for the genetic etiological identification of recurrent miscarriage.

[Prenatal diagnosis and genetic analysis of a rare case with 8p deletion and duplication].

OBJECTIVE: To explore the genetic etiology for a child featuring mental retardation, language delay and autism. METHODS: G-banding chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) were carried out for the child and her parents. RESULTS: The child was found to have a 46,XX,dup(8p?) karyotype, for which both of her parents were normal. SNP-array revealed that the child has harbored a 6.8 Mb deletion in 8p23.3p23.1 and a 21.8 Mb duplication in 8p23.1p12, both of which were verified as de novo pathogenic copy number variants. CONCLUSION: The clinical features of the child may be attributed to the 8p deletion and duplication. SNP-array can facilitate genetic diagnosis for children featuring mental retardation in conjunct with other developmental anomalies.

[Genetic analysis of a case with a supernumerary marker derived from chromosome 9].

OBJECTIVE: To delineate a small supernumerary marker chromosome (sSMC) derived from chromosome 9 with combined cytogenetic and molecular methods. METHODS: For a pregnant woman with fetal ultrasound revealing left ventricular punctate hyperechoic echo, and a high risk for monosomy or partial deletion of chromosome 8, chromosome 9 trisomy, monosomy or partial deletion of chromosome 11 by non-invasive prenatal testing, and an abnormal MOM value revealed by mid-term serum screening, amniocentesis was performed for G banded chromosomal analysis and single nucleotide polymorphism array (SNP-array) assay. Peripheral blood samples of the woman and her spouse were also collected for the above tests. In addition, the woman was further subjected to C banding karyotyping analysis and fluorescence in situ hybridization (FISH) assay. RESULTS: The G-banded karyotype of the pregnant women was 47,XX,+mar[20]/46,XX[80], whilst C-banding analysis showed a deep stain in the middle of the sSMC (suggestive of centromeric region) and light stain at both ends (suggestive of euchromatism). FISH combined with DAPI banding analysis using 9pter/9qter probes revealed a karyotype of 47,XX,+mar.ish i(9)(9p10)(9p++)[2]/46,XX[18], whilst SNP-array has revealed a 68.1 Mb duplication in the 9p24.3q13 region. A database search has suggested the duplication to be likely pathogenic. No abnormality was found in her fetus and spouse by karyotyping and SNP-array analysis. CONCLUSION: Through combined cytogenetic and molecular genetic analysis, a sSMC derived from chromosome 9 was delineated, which has enabled genetic counseling for the couple.

[Clinical and genetic analysis of a patient with 10q26.3 microdeletion in conjunct with 18q22.3q23 microduplication].

OBJECTIVE: To explore the genetic etiology for a patient featuring intellectual disability and torticollis. METHODS: Peripheral blood sample was collected from the patient and subjected to G-banded karyotyping analysis and single nucleotide polymorphism array (SNP-array) assay. RESULTS: The patient was found to have a chromosomal karyotype of 46,XX. SNP-array revealed that she has harbored a 3.8 Mb microdeletion at 10q26.3 which has encompassed 21 OMIM genes including EBF3 and ECHS1, and a 7.3 Mb duplication at 18q22.3q23 which has encompassed 19 OMIM genes including TSHZ1 and TXNL4A. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the 10q26.3 deletion was predicted to be pathogenic, whilst the 18q22.3q23 duplication was predicted to be variation of unknown significance. CONCLUSION: The clinical phenotype of the patient may be mainly attributed to the 10q26.3 microdeletion, and haploinsufficiency of the EBF3 gene may account for her intellectual deficiency. Above finding has provided a basis for genetic counseling for the patient.

Case Report: Novel compound heterozygous variants in CHRNA1 gene leading to lethal multiple pterygium syndrome: A case report.

Background: Lethal multiple pterygium syndrome (LMPS) is a rare autosomal recessive inherited disorder typically characterized by intrauterine growth retardation, multiple pterygia, and flexion contractures. Case presentation: We herein report a Chinese case with a history of three adverse pregnancies demonstrating the same ultrasonic phenotypes, including increased nuchal translucency, edema, fetal neck cystoma, reduced movement, joint contractures, and other congenital features. Whole-exome sequencing (WES) revealed novel compound heterozygous variants in the CHRNA1 gene NM_000079.4: c.[1128delG (p.Pro377LeufsTer10)]; [505T>C (p.Trp169Arg)] in the recruited individual, and subsequent familial segregation showed that both parents transmitted their respective mutation. Conclusion: For the first time, we identified an association between the CHRNA1 gene and the recurrent lethal multiple pterygium syndrome (LMPS) in a Chinese family. This finding may also enrich the mutation spectrum of the CHRNA1 gene and promote the applications of WES technology in etiologic diagnosis of ultrasound anomalies in prenatal examination.

[Application of chromosomal microarray analysis in the diagnosis of genetic etiology of spontaneous abortions].

OBJECTIVE: To explore the genetic etiology of spontaneous abortions by using chromosomal microarray analysis (CMA). METHODS: Fetal tissues derived from 106 spontaneous abortion samples were subjected to CMA assay to detect genome copy number variants (CNVs). RESULTS: The test was successful in 94 cases (88.68%). Fifty four chromosomal abnormalities were detected, which included 44 numerical chromosomal aberrations mainly consisting of aneuploidies, triploidies and mosaicisms. Four pathogenic CNVs were detected, and two of which involved the Cri-du-chat syndrome regions. In addition, 6 chromosomal mosaicism were detected. CONCLUSION: Numerical chromosomal aberrations and CNVs are the main causes for early spontaneous abortions. CMA can effectively reveal the genetic etiology of spontaneous abortions. Spontaneous abortions at gestational weeks 10 to 11+6 has the highest rate for chromosomal abnormalities, which may provide valuable information for clinical counseling.

Case Report: Prenatal Whole-Exome Sequencing Identified a Novel Nonsense Mutation of the KCNH2 Gene in a Fetus With Familial 2q14.2 Duplication.

Background: Pathogenic mutations in the KCNH2 gene were associated with long QT syndrome 2 (LQT2), which typically manifest in a prolonged QT interval and may lead to recurrent syncopes, seizure, or sudden death. Limited reports indicated that the KCNH2 mutations would result in LQT2 combined with tetralogy of fallot. Our goal was to present an additional case of LQT2 combined with the tetralogy of fallot in a fetus with a novel KCNH2 mutation. Case presentation: Enrolled in this study was a 23-year-old pregnant woman from Quanzhou Fujian province, China. In her pregnancy, fetal ultrasound anomalies were identified, including tetralogy of fallot, coronary sinus enlargement, and persistent left superior vena cava. No chromosomal abnormality was detected by fetal karyotype analysis. However, 238.1-kb duplication in the 2q14.2 region containing the GLI2 gene was observed in the fetus by chromosomal array analysis, which was inherited from the mother with normal clinical features and interpreted as a variant of uncertain significance (VOUS). Furthermore, whole-exome sequencing (WES) detection identified a novel nonsense c.1907C > G (p.S636*) mutation in the KCNH2 gene in the fetus, and it was classified as a likely pathogenic variant, according to the ACMG guidelines. Parental verification analysis indicated that c.1907C > G (p.S636*) mutation was inherited from the mother. Conclusion: In this study, we believe that 2q14.2 duplication may not be the reason for fetal heart defects; moreover, we described an additional case with KCNH2 gene mutation, which may lead to LQTS and be associated with congenital heart defects. In addition, our study further confirms the application value of the WES technology in prenatal genetic etiology diagnosis of fetuses with structural anomalies and unexplained structural variants.

Molecular cytogenetic analysis of partial monosomy 10p and trisomy 10q resulting from familial pericentric inversion (10): a first case report in Chinese population.

BACKGROUND: Chromosome aberrations of 10p monosomy and 10q trisomy resulting from parental pericentric inversion 10 are extremely rare, and to date, very few reports have been published on the matter. CASE PRESENTATION: A 30-year-old pregnant woman with recurrent pregnancy loss is enrolled in this research. In this pregnancy, spontaneous abortion occurred in the first trimester of her pregnancy. Chromosomal microarray analysis of the abortion tissue showed a partial 10p monosomy (arr[GRCh37] 10p15.3p11.21(100,047_34,848,853) × 1) and a duplication of 10q (arr[GRCh37] 10q26.13q26.3(126,093,990_135,426,386) × 3). Further parental karyotype analysis indicated that the chromosomal abnormalities in the fetus was resulted from paternal pericenric inversion inv(10)(p11.21q26.13). This study presents the first case of a large deletion of 10p combined with 10q trisomy, resulting in pregnancy loss. Of these two manifestations, the large deletion of chromosome 10p may be the primary reason for spontaneous abortion in this subject. CONCLUSIONS: This study presents the first case of partial 10p monosomy associated with 10q trisomy in Chinese population. It provides more information on the chromosome aberration of 10p monosomy and 10q trisomy and further strengthens the application value of microarray in the molecular etiological diagnosis of recurrent spontaneous abortion.

Identification of a Rare Variant of c.1777G>A (p.G593S) in the COL1A1 Gene as the Etiology of Recurrent Osteogenesis Imperfecta by Whole-Exome Sequencing.

Background: Osteogenesis imperfecta (OI) is a rare heterogeneous disorder typically featured by fragile bones and susceptibility to fracture. The aim of the present study was to explore the genetic etiology of familial recurrent OI and the genotype-phenotype correlation. Methods: Karyotyping, chromosomal microarray analysis, and whole-exome sequencing (WES) were performed to determine the genetic etiology of OI in the enrolled family. Western blotting analysis was carried out using the fetal skin tissue for type I collagen production analysis. Results: At the first pregnancy, a c.1777G>A mutation in the COL1A1 gene was detected in the fetus who exhibited skeletal dysplasia. In this second pregnancy, severe fetal skeletal dysplasia was also presented without significant chromosomal abnormality detected by karyotype and chromosomal microarray analysis in the fetus. Further WES results demonstrated a de novo missense mutation of c.1777G>A (p.G593S) in the fetus, which was classified as a pathogenic variant according to the ACMG guidelines. The recurrent mutation in the two fetuses hinted at the possible existence of gonadal mosaicism in the parents, while no mutation in the COL1A1 gene was identified in the DNA from the father's sperm. In addition, Western blot results demonstrated no reduced type I procollagen production in the affected fetus compared with the age-matched controls. Conclusions: To the best of our knowledge, this is the first study that identified a rare variant of c.1777G>A in the COL1A1 gene that led to recurrent OI in the Chinese population. Additionally, we believe that this rare variant of c.1777G>A in the COL1A1 gene will lead to OI type II. The results of the present study further verify the application value of WES in identifying fetuses with ultrasound anomalies.

Case Report: Prenatal Diagnosis of a Novel Variant c.251dupT (p.N87Kfs*6) in BCOR Resulting in Oculofaciocardiodental Syndrome Using Whole-Exome Sequencing.

Background: Oculofaciocardiodental (OFCD) syndrome is an X-linked dominant syndrome caused by BCOR variants, which manifests only in females and presumed leading to male lethality. Herein, we aim to present a prenatal diagnosis for OFCD syndrome associated with a novel hemizygous variant in BCOR gene. Case presentation: A 29-year-old pregnant woman from Quanzhou Fujian Province, China, with fetal ultrasound anomalies, was enrolled in this study. A normal 46, XY karyotype with no abnormalities was observed in the fetus detected on microarray. Furthermore, a whole-exome sequencing (WES) detection result demonstrated that a novel hemizygous variant of c.251dupT (p.N87Kfs*6) in the BCOR gene was identified in the fetus, which was a frameshift mutation and classified as a likely pathogenic variant, and may lead to OFCD syndrome according to the clinical feature of the fetus. In this case, male lethality had not occurred by the end of the second trimester, then termination of the pregnancy was conducted at a gestational age of 26 weeks. Sanger sequencing of parental samples revealed that the variant was maternally transmitted, which was consistent with the OFCD syndrome phenotypic features observed in her. Conclusions: In the study, we first present the affected male with a novel variant in BCOR that leads to the OFCD syndrome. Additionally, our study broadened the spectrum of BCOR results in the OFCD syndrome and provided the valuable references for prenatal genetic consultation.

[Genetic Analysis and Prenatal Diagnosis of Thalassemia in Couples of Childbearing Age in Quanzhou Region Fujian Province, China].

OBJECTIVE: To explore the genotypes and prenatal diagnosis of thalassemia in couples of childbearing age in Quanzhou, Fujian Province. METHODS: Blood routine and hemoglobin electrophoresis were performed for initial thalassemia screening in 76 328 couples in Quanzhou region from July 2017 to July 2020. The couples with positive initial screening results further underwent thalassemia gene test. Couples carrying homotypic thalassemia genes underwent prenatal diagnosis in the second trimester. RESULTS: Among 76 328 couples of childbearing age, 1 809 couples of positive initial thalassemia screening were identified, with the positive rate about 2.37%. Further results of genetic detection of the 1 809 couples showed that 985 cases were diagnosed as α- thalassemia, of which --sea/αα was the most frequency, followed by -α3.7/αα and ααQS/αα; 296 cases were diagnosed as ß-thalassemia, the most frequency mutations were 654M/N and 41-42M/N; 26 cases of compound α and ß-thalassemia were detected. In addition, 3 rare cases of thalassemia were detected, including --THAI/αα, SEA-HPFH, and -α6.9/--sea. Among them, 108 couples were confirmed as homologous thalassemia, with the detection rate about 5.97%, including 96 couples of homologous α-thalassemia, 9 couples of homologous ß-thalassemia, and 3 couples with one had compound α- and ß-thalassemia. Among them, 17 couples with homologous α-thalassemia underwent prenatal diagnosis in the second trimester, of which 1 case of Hb Bart's Hydrops Syndrome, 3 cases of HbH disease, 9 cases of silent thalassemia or α-thalassemia minor, and 4 cases of healthy fetuses were detected. Fetal chromosome karyotype analysis showed that 16 cases were normal and 1 case diagnosed as Down syndrome. CONCLUSION: Thalassemia screening in pre-marital and pre-pregnancy, and prenatal diagnosis can effectively reduce the birth of children with thalassemia intermediate and thalassemia major. It is necessary to perform chromosome karyotype analysis at the same time as prenatal diagnosis of thalassemia gene in order to avoid fetus with abnormal chromosome.

[The value of combined detection of HbA2 and HbF for the screening of thalassemia among individuals of childbearing ages].

OBJECTIVE: To assess the application value of combined detection of HbA2 and HbF for the screening of thalassemia among a population of childbearing age in Quanzhou, Fujian, and determine the optimal cut-off values for the region. METHODS: Capillary hemoglobin electrophoresis and genetic testing for α and ß globin gene mutations were simultaneously carried out on 11 428 patients with suspected thalassemia. Statistical methods were used to analyze the distribution of various types of thalassemia and compare the performance of HbA2 and HbF measurement for the screening of various types of thalassemia. The optimal cut-off values for HbA2 and HbF were determined with the ROC curves. RESULTS: 4591 patients with α, ß, and αß compound thalassemia were identified by genetic testing. The most common genotypes for α and ß thalassemia included --SEA/αα and ß654/ßN, ß41-42/ßN, and ß17/ßN. The ROC curves were drawn to compare the performance of HbA2 screening for α-, ß-, αß-compound, static α-, mild α-, and intermediate α-thalassemia, and the maximum area under the curves was 0.674, 0.984, 0.936, 0.499, 0.731, 0.956, and the optimal cut-off values for HbA2 were 2.45%, 3.25%, 3.65%, 2.95%, 2.55%, 1.75%, respectively. CONCLUSION: HbA2 is an efficient indicator for identifying intermediate types of α-, ß-, and αß compound thalassemia. The combination of HbA2 and HbF measurement can effectively detect carriers for ß-thalassemia mutations.

[A case of neonatal Cornelia de Lange syndrome caused by a novel variant of SMC1A gene].

OBJECTIVE: To explore the genetic etiology of a neonate with suggestive features of Cornelia de Lange Syndrome (CdLS). METHODS: Chromosome karyotyping, copy number variation sequencing (CNV-seq) and whole exome sequencing (WES) were carried out for the child. Meanwhile, peripheral venous blood samples were taken from his parents for verifying the suspected pathogenic variants detected in the child. RESULTS: The child has exhibited developmental delay, microcephaly, ptosis, micrognathia, and low ear setting, and was suspected as CdLS. No abnormality was found by karyotyping and CNV-seq analysis. WES has detected 5 heterogeneous variants and 1 hemizygous variant on the X chromosome. Combining the genetic pattern and result of family verification, a hemizygous C.3500T>C (p.ile1167thr) of the SMC1A gene was predicted to underlay the clinical manifestations of the patient. This variant was not recorded in the dbSNP and gnomAD database. PolyPhen2, Provean, SIFT all predicted the variant to be harmful, and PhastCons conservative prediction is was a conservative mutation. ACMG variant classification standard evidence supports are PM2, PP2, and PP3. CONCLUSION: The novel c.3500T>C (p.Ile1167Thr) missense mutation of the SMC1A gene probably underlay the genetic etiology of CdLS in this child. Above results has enriched the mutation spectrum of CdLS type II, and facilitated clinical counseling for this family.

Molecular Characterization Analysis of Thalassemia and Hemoglobinopathy in Quanzhou, Southeast China: A Large-Scale Retrospective Study.

Background: There are limited reports available on investigations into the molecular spectrum of thalassemia and hemoglobinopathy in Fujian province, Southeast China. Here, we aim to reveal the spectrum of the thalassemia mutation and hemoglobinopathy in Quanzhou prefecture, Fujian province. Methods: We collected data from a total of 17,407 subjects with the thalassemia trait in Quanzhou prefecture. Gap-PCR, DNA reverse dot blot hybridization, and DNA sequencing were utilized for common and rare thalassemia gene testing. Results: In our study, we identified 7,085 subjects who were carrying thalassemia mutations, representing a detection rate of 40.70% (7,085/17,407). Among them, 13 different α-thalassemia gene mutations were detected, with the most common mutation being - SEA (69.01%), followed by -α3.7 (21.34%) and -α4.2 (3.96%). We also discovered 26 ß-thalassemia gene mutations, with the mutations of IVS-II-654 (C > T) (36.28%) and CD41/42(-TCTT) (29.16%) being the most prevalent. Besides, a variety of rare thalassemia variants were identified. Among them, the - FIL , ß Malay , ß IVS-I-130, and ß IVS-II-672 mutations were identified in Fujian province for the first time. Additionally, we detected 78 cases of hemoglobinopathies, of which Hb Owari was the first reported case in Fujian province and Hb Miyashiro was the first case identified in the Chinese population. Conclusion: Our study indicates that there is a diverse range of thalassemia mutations, and it also reveals the mutation spectrum of rare thalassemia and hemoglobinopathies in Quanzhou, Fujian province. It provides valuable data for the prevention and control of thalassemia in Southeast China.

[Non-invasive prenatal testing and genetic diagnosis of a case of Pallister-Killian syndrome].

OBJECTIVE: To apply combined non-invasive prenatal testing (NIPT), chromosomal karyotyping and chromosomal microarray for the screening and prenatal diagnosis of a fetus with supernumerary small marker chromosome (sSMC). METHODS: Standard NIFTY and full gene NIFTY kits were applied to detect free DNA (cfDNA) isolated from peripheral blood sample of a pregnancy woman. Amniocentesis was carried out for the woman for an abnormal NIPT result. G-banded karyotyping and single nucleotide polymorphism array (SNP array) were used to determine the karyotype and copy number variants in the fetus. The result was validated with a fluorescence in situ hybridization (FISH) assay. RESULTS: Both the standard NIFTY and full gene NIFTY indicated abnormal dup(chr12:707 334-33 308 759), for which the T score value of copy number anomaly in full gene NIFTY is 6.823, which is higher than the standard NIFTY's T-score value of 3.9535. The two NIFTY results were both above the normal threshold ± 3. Conventional G-banding analysis of amniocytes showed that the fetus has a karyotype of 47,XY,+mar. SNP-array delineated duplication of 12p (arr [hg19]12p13.33p11.1 (173 786_34 385 641)× 4, which was verified by FISH. Based on the above results, the fetus was diagnosed as a novel case of Pallister-Killian syndrome. CONCLUSION: NIPT has a certain value for the prenatal detection of PKS. Combined use of multiple techniques can facilitate delineation of the source of sSMC.

Cytogenetic and molecular analysis of distal 4q duplication with distinctive phenotype using single-nucleotide polymorphism array.

AIMS: There is little knowledge about partial trisomy 4q and the genotype-phenotype correlation. In this study, we presented the detail of two Chinese families with partial distal 4q duplication in an attempt to clarify the correlation between the genotype and the phenotype. METHODS: Two pedigrees with distal 4q duplication were enrolled in this study. Karyotype analysis and single-nucleotide polymorphism (SNP) array detection were performed for prenatal diagnosis. Fluorescence in situ hybridization analysis. (FISH) was conducted to verify the copy number variants. RESULTS: Two families with partial trisomy 4q were identified. The fetus in pedigree 1 exhibited multiple ultrasound anomalies including intrauterine growth restriction and an atrioventricular septal defect who had a duplication of 4q28.3-qter associate with 6p25.2-p25.3 deletion, which resulted from balanced translocation carried by his father t(4;6)(q28.3;p25.2). The fetus in pedigree 2 had a distal 4q28.3-qter duplication combined with monosomy of Xp21.3-p22.3, and the karyotype was described as 46,X,der(X)t(X;4)(p21.3;q28.3)mat, which originally inherited from the pregnant woman who exhibited a mild clinical phenotype limited to short stature. CONCLUSIONS: In our study, we for the first time identified the partial trisomy 4q associate with 6p or Xp deletion. In addition, our finding further strengthens that mild clinical phenotype in 4q duplication case may be due to the spreading of X inactivation to the autosomal in derivation of chromosome X.

[Genetic Testing for Alpha and Beta Thalassemia in Children in Quanzhou Region of Fujian Province in China].

OBJECTIVE: To analyze the genotypes and distribution of thalassemia in children in Quanzhou Region so as to provide reference for the prevention and control of thalassemia. METHODS: A total of 1 302 children with suspected thalassemia were collected from January 2014 to April 2020 in Quanzhou Region. The deletional α-thalassemia was detected by Gap-PCR, and DNA reverse dot blot (RDB) hybridization was used to detect α- and ß-thalassemia mutations. RESULTS: In the 1 302 cases, 667 cases were identified as thalassemia carriers, and the positive detection rate was about 51.23%. Among them, 380 cases of α-thalassemia gene were detected, and --SEA/αα was the most common genotype with the composition rate about 69.21%. Forty-two cases were identified as HbH disease, and -α3.7/--SEA was the most common genotype. While, 274 cases were identified as ß-thalassemia, and ßIVS-Ⅱ-654/ßN (35.40%) and ßCD41-42/ßN (33.94%) were the most common genotypes. Seventeen cases of ß-thalassemia major/intermedia were identified, and the most common genotypes were ßIVS-Ⅱ-654/ßIVS-Ⅱ-654 and ßIVS-Ⅱ-654/ßCD17. Meanwhile, 13 cases of α- complex ß- thalassemia were detected. Among them, 1 case of ß-thalassemia gene rare mutation Term CD+32 was firstly detected in Fujian Province, and 1 case of CD14-15 mutation was firstly detected in Quanzhou Region. In addition, 3 cases of abnormal hemoglobin disease were identified, in which 2 cases were Hb Q-Thailand and 1 case was Hb G-Honolulu. CONCLUSION: There are various genotypes of thalassemia in children in Quanzhou Region, and many children with thalassemia major or intermedia. Therefore, further prevention and control of thalassemia need to be strengthened for reducing the birth of thalassemia major or intermedia.