Compound heterozygosity for Southeast Asian hereditary persistence of fetal hemoglobin and ß0-thalassemia results in thalassemia intermedia: Pedigree analysis and genetic research in a family from South China. A case report.

RATIONALE: Compound heterozygotes for deletional ß-thalassemia can be difficult to diagnose due to its diverse clinical presentations and no routine screenings. This can lead to disease progression and delay in treatment. PATIENT CONCERNS: We reported pedigree analysis and genetic research in a family with rare ß-thalassemia. DIAGNOSIS: Pedigree analysis and genetic research demonstrated that the patient was a compound heterozygote for ß-thalassemia CD17/Southeast Asian hereditary persistence of fetal hemoglobin deletion, inherited from the parents. Magnetic resonance imaging T2* examination revealed severe iron deposition in the liver. Echocardiography revealed endocardial cushion defect. INTERVENTIONS: The patient was treated with Deferasirox after receiving the final molecular genetic diagnosis. The initial once-daily dose of Deferasirox was 20 mg/kg/d. OUTCOMES: The patient discontinued the medication three months after the first visit. Two years later, the patient visited the Department of Hepatobiliary and Pancreatic Diseases. He was recommended to undergo splenectomy after surgical repair of the congenital heart disease. However, the patient refused surgical treatment because of the economic burden. LESSONS: We report that fetal hemoglobin is a sensitive indicator for screening large deletions of the ß-globin gene, which can be effectively confirmed by the multiplex ligation-dependent probe amplification assay. In non-transfusion-dependent thalassemia patients, iron status assessment should be regularly performed, and iron chelation treatment should be initiated early. This case will provide insights for the diagnosis of rare genotypes of ß-thalassemia and has important implications for genetic counseling.

The timely diagnosis of 49, XXXXY with the combined detection of MLPA, karyotype, and QF-PCR in a newborn with multiple congenital malformations: a case report.

Background: 49, XXXXY is a rare sex chromosomal aneuploidy syndrome. The patients usually are diagnosed several months or years after birth. Herein a neonate with respiratory distress and multiple malformations was diagnosed with 49, XXXXY syndrome by an economical method of multiplex ligation-dependent probe amplification (MLPA) followed karyotype analysis. Case Description: An infant was born via spontaneous vaginal delivery at 41+3 weeks' gestation and hospitalized due to neonatal asphyxia. He was the first child to a 24-year-old gravida1, para1 (G1P1) mother. The newborn was characterized low birth weight (2.4 Kg, below the 3rd percentile), and an Apgar score of 6 at 1 minute, 8 at 5 minutes, and 9 at 10 minutes. The physical examinations of the patient revealed ocular hypertelorism, epicanthal folds, low nasal bridge, high-arched palate, cleft palate, micrognathia, low-set ears, microcephaly, hypotonia, and micropenis. Echocardiography revealed atrial septal defects (ASD). The brainstem auditory evoked potential (BAEP) reflected auditory function impairment. Genetic testing methods, including MLPA, karyotyping, and quantitative fluorescent polymerase chain reaction (QF-PCR), were performed for definitive diagnosis, which confirmed 49, XXXXY syndrome. Conclusions: The presentation of the 49, XXXXY newborn was atypical, they may only include low birth weight, multiple malformations and a characteristic facial appearance which were consistent with the characteristics of autosomal and sex chromosome aneuploidies. At this time, the economical and rapid method of MLPA to screen the number of chromosome, and then choose the appropriate means to make the final diagnosis and improve the quality of life of patients with timely therapy.

Integrative analyses of RNA-seq and ChIP-seq Reveal MITF as a Target Gene of TFPI-2 in MDA231 Cells.

Breast cancer is the most prevalent cancer in female patients worldwide. Tissue factor pathway inhibitor 2 (TFPI-2) is identified as an important tumor suppressor in various cancers. Recent studies have shown that TFPI-2 translocates into the nucleus, where it modulates the transcription of the matrix metalloproteinase-2 (MMP-2) gene. However, its biological role and molecular mechanisms in the progression of breast cancer remain unclear. In this study, we identified 5125 differentially expressed genes (DEGs) from RNA sequencing (RNA-seq) in TFPI-2-overexpressing MDA231 cells compared with control cells. Gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) analysis shown that cell cycle, cell differentiation, proteoglycans in cancer, and pathways associated with cancer were highly enriched in downregulated DEGs. Integration of the RNA-seq and ChIP-sequencing (ChIP-seq) data identified 73 genes directly controlled by TFPI-2 in MDA231 cells. Among them, melanocyte inducing transcription factor (MITF) gene expression was repressed by TFPI-2, which was further verified by a luciferase reporter assay and ChIP-quantitative PCR. Our study provides evidence of a novel role of TFPI-2 in human breast cancer involving targeting of the MITF.

Resveratrol improves follicular development of PCOS rats via regulating glycolysis pathway and targeting SIRT1.

Polycystic ovary syndrome (PCOS) is a disease characterized by metabolic disorders. This study aimed to examine the effects of resveratrol treatment on ovulation in the PCOS rat model. Quantitative real-time PCR and immunohistochemistry were used to determine the mRNA and protein expression levels. TNUEL assay was used to evaluate cell apoptosis in ovary. The metabolites were evaluated by liquid chromatography with tandem mass spectrometry. Resveratrol alleviated disrupted estrous cycle and improved granular cell layers, and reversed the decreased proliferation and increased cell apoptosis of granulosa cells in the ovarian tissues of PCOS rats. Resveratrol restored the changes in the mRNA expression levels in the rate-limiting genes of glycolysis in the PCOS ovary. The expression of lactate dehydrogenase A (LDH-A), pyruvate kinase isozyme M2 (PKM2), and sirtuin 1 (SIRT1) was significantly downregulated in ovarian tissues of the PCOS rats; while the resveratrol treatment significantly increased the expression of LDH-A, PKM2, and SIRT1 in the ovarian tissues of PCOS rats. Collectively, the protective effects of resveratrol in the PCOS rats may be associated with the regulation of glycolysis-related mediators including PKM2, LDH-A, and SIRT1. Resveratrol may represent a good candidate in alleviating the development of PCOS.

Accurate genotype diagnosis of Hong Kongαα thalassemia based on third-generation sequencing.

Background: The Hong Kongαα (HKαα) allele is a complex structural rearrangement of the α-globin gene containing -α3.7 and αααanti 4.2 crossover junctions. Clinically, individuals carrying the HKαα allele are often misdiagnosed or missed using conventional thalassemia gene detection technology. This study aims to identify and validate different HKαα thalassemia subtypes using third-generation sequencing (TGS) technology. Methods: Between January 2015 and June 2021, 32 patients suspected of having HKαα thalassemia were included in this study. Genomic DNA was extracted, and gap-polymerase chain reaction (PCR), two-round nested PCR, multiplex ligation-dependent probe amplification (MLPA), and TGS were used for thalassemia gene detection. Results: The results of HKαα/αα and HKαα/-α3.7 were similar to -α3.7/αα using the gap-PCR method. Two-round nested PCR could be used to verify the HKαα gene, but could not distinguish the subtypes of HKαα thalassemia. The MLPA assay was used to detect the change in the copy number of the α-globin gene, but it could not determine whether -α3.7 and αααanti 4.2 were in cis or in trans. Long-read TGS technology could accurately detect the HKαα allele and distinguish the genotypes of HKαα/αα, HKαα/-α3.7, HKαα/-α4.2, and HKαα/--SEA without pedigree analysis. The contiguous sequence of the HKαα allele was detected using the TGS approach. This study also demonstrated that individuals with HKαα/αα and ßN/ßN genotypes tended to have normal hematological phenotypes. Conclusions: Long-read TGS is a reliable and efficient approach for accurate detection of HKαα thalassemia, which can be widely used in clinical practice. Accurate molecular diagnosis of HKαα thalassemia will benefit clinical genetic counseling and prenatal diagnosis.

[Genetic diagnosis of a case of Smith-Magenis syndrome due to a rare small-scale deletion].

OBJECTIVE: To report on a case of Smith-Magenis syndrome (SMS) due to a rare small-scale deletion. METHODS: Muscle samples from the the third fetus was collected after the in Medical history and clinical data of the patient were collected. The child and his parents were subjected to chromosome karyotyping analysis, multiplex ligation-dependent probe amplification (MLPA) and copy number variation sequencing (CNV-seq). RESULTS: The child was found to have a normal karyotype. MLPA and CNV-seq detection showed that he has harbored a 1.22 Mb deletion and a 0.3 Mb duplication in the 17p11.2 region. Neither of his parents was found to have similar deletion or duplication. CONCLUSION: The child was diagnosed with SMS due to a rare 1.22 Mb deletion in the 17p11.2 region, which is among the smallest deletions associated with this syndrome.

Hb New York, preliminary results concerning the hematologic characteristics and the effects on thalassemia.

BACKGROUND: The hematological phenotype and genotype analysis of hemoglobin New York (Hb New York) combined with α or ß thalassemia has been rarely reported, and whether there is any effect of Hb New York on thalassemia has not been well explored. METHODS AND RESULTS: In this study, peripheral blood samples from 346 Hb New York carriers were collected for blood cell parameter analysis. When comparing Hb New York heterozygotes, Hb New York combined with α0 thalassemia or α+ thalassemia, we found that the differences in hemoglobin (HGB), MCV and MCH values were statistically significant (P < 0.05). The HGB, MCV and MCH values of α thalassemia patients were not different from Hb New York combined with α thalassemia group (P > 0.05). When Hb New York heterozygotes were compared to Hb New York combined with ß0 thalassemia or ß+ thalassemia, the differences in MCV and MCH values were statistically significant (P < 0.05). However, the differences in MCV and MCH values were not statistically significant between Hb New York combined with ß thalassemia and ß thalassemia (P > 0.05). CONCLUSIONS: Our study shows that the hematological characteristics of Hb New York combined with thalassemia are similar to the corresponding thalassemia, and Hb New York does not aggravate the clinical manifestations of thalassemia.

[Analysis of Thalassemia Gene Carriers in 19 482 Pregnant Women from 2015 to 2019 in Guilin, Guangxi].

OBJECTIVE: To investigate the types and frequencies of thalassemia genes carried by the pregnant women in Guilin, Guangxi Zhuang Autonomous Region, China. METHODS: From January 2015 to December 2019, blood samples of the pregnant women who visited the Outpatients of Obstetrics clinic and Eugenics Genetic clinic in Affiliated Hospital of Guilin Medical University were collected. Gap-PCR was used to detect deletional α-thalassemia, PCR-RDB to detect the gene mutations of non-deletional α-thalassemia and ß-thalassemia, and MLPA or DNA sequencing to detect rare thalassemia mutations. Different types and frequencies of thalassemia mutations carried by pregnant women were analyzed statistically. RESULTS: A total of 19 482 blood samples were collected, including 3 801 thalassemia gene carriers (19.51%). Seven types of α-thalassemia gene mutation were detected with a carrier rate of 15.43%. Among them, --SEA deletion (7.32%), -α3.7 deletion (3.97%), and -α4.2 deletion (1.4%) were the commonest types. Twelve types of ß-thalassemia mutations were detected with a carrier rate of 5.02%. Among them, CD41-42 (-TCTT) (2.32%), CD17 (AAG>TAG) (1.23%), and IVS-II-654 (C>T) (0.55%) were the commonest types. In addition, 107 cases of rare thalassemia gene mutations and abnormal hemoglobin were found at the same time. CONCLUSION: Guilin is a high-risk area for thalassemia. Alpha-thalassemia is dominated by --SEA deletion, -α3.7 deletion, and -α4.2 deletion, while ß-thalassemia is by CD41-42 (-TCTT), CD17(AAG>TAG), and IVS-II-654(C>T).

An Efficient Algorithm for Deep Stochastic Contextual Bandits.

In stochastic contextual bandit (SCB) problems, an agent selects an action based on certain observed context to maximize the cumulative reward over iterations. Recently there have been a few studies using a deep neural network (DNN) to predict the expected reward for an action, and the DNN is trained by a stochastic gradient based method. However, convergence analysis has been greatly ignored to examine whether and where these methods converge. In this work, we formulate the SCB that uses a DNN reward function as a non-convex stochastic optimization problem, and design a stage-wise stochastic gradient descent algorithm to optimize the problem and determine the action policy. We prove that with high probability, the action sequence chosen by this algorithm converges to a greedy action policy respecting a local optimal reward function. Extensive experiments have been performed to demonstrate the effectiveness and efficiency of the proposed algorithm on multiple real-world datasets.

OctSurf: Efficient hierarchical voxel-based molecular surface representation for protein-ligand affinity prediction.

Voxel-based 3D convolutional neural networks (CNNs) have been applied to predict protein-ligand binding affinity. However, the memory usage and computation cost of these voxel-based approaches increase cubically with respect to spatial resolution and sometimes make volumetric CNNs intractable at higher resolutions. Therefore, it is necessary to develop memory-efficient alternatives that can accelerate the convolutional operation on 3D volumetric representations of the protein-ligand interaction. In this study, we implement a novel volumetric representation, OctSurf, to characterize the 3D molecular surface of protein binding pockets and bound ligands. The OctSurf surface representation is built based on the octree data structure, which has been widely used in computer graphics to efficiently represent and store 3D object data. Vanilla 3D-CNN approaches often divide the 3D space of objects into equal-sized voxels. In contrast, OctSurf recursively partitions the 3D space containing the protein-ligand pocket into eight subspaces called octants. Only those octants containing van der Waals surface points of protein or ligand atoms undergo the recursive subdivision process until they reach the predefined octree depth, whereas unoccupied octants are kept intact to reduce the memory cost. Resulting non-empty leaf octants approximate molecular surfaces of the protein pocket and bound ligands. These surface octants, along with their chemical and geometric features, are used as the input to 3D-CNNs. Two kinds of CNN architectures, VGG and ResNet, are applied to the OctSurf representation to predict binding affinity. The OctSurf representation consumes much less memory than the conventional voxel representation at the same resolution. By restricting the convolution operation to only octants of the smallest size, our method also alleviates the overall computational overhead of CNN. A series of experiments are performed to demonstrate the disk storage and computational efficiency of the proposed learning method. Our code is available at the following GitHub repository: https://github.uconn.edu/mldrugdiscovery/OctSurf.

Asynchronous Parallel Stochastic Quasi-Newton Methods.

Although first-order stochastic algorithms, such as stochastic gradient descent, have been the main force to scale up machine learning models, such as deep neural nets, the second-order quasi-Newton methods start to draw attention due to their effectiveness in dealing with ill-conditioned optimization problems. The L-BFGS method is one of the most widely used quasi-Newton methods. We propose an asynchronous parallel algorithm for stochastic quasi-Newton (AsySQN) method. Unlike prior attempts, which parallelize only the calculation for gradient or the two-loop recursion of L-BFGS, our algorithm is the first one that truly parallelizes L-BFGS with a convergence guarantee. Adopting the variance reduction technique, a prior stochastic L-BFGS, which has not been designed for parallel computing, reaches a linear convergence rate. We prove that our asynchronous parallel scheme maintains the same linear convergence rate but achieves significant speedup. Empirical evaluations in both simulations and benchmark datasets demonstrate the speedup in comparison with the non-parallel stochastic L-BFGS, as well as the better performance than first-order methods in solving ill-conditioned problems.

The pedigree analysis and prenatal diagnosis of Hong Kongαα Thalassemia and the sequence analysis of Hong Kongαα Allele.

BACKGROUND: Thalassemia is one of the most common monogenic hemolytic disorders in the world. Hong Kongαα (HKαα) thalassemia was initially found among the people of southern China. Because of the complexity of genetic changes in HKαα thalassemia, we lack a precise sequence analysis of the HKαα allele. Here we aim to detect the specific genotype and trace the law of inheritance of this rare genotype. METHODS: We recruited an unprecedented huge pedigree containing 11 individuals carrying the HKαα thalassemia gene and 4 nongenetic-related patients suffering from HKαα from south China. Regular hematological analysis and routine genetic screening were performed on the pedigree and two-round nested PCR (polymerase chain reaction) for HKαα thalassemia were performed on each individual. The first-generation gene sequencing was performed on six individuals, including four nongenetic-related patients. RESULT: We found that five family members were positive for the HKαα allele. Patients Ⅱ-2, Ⅲ-1, and Ⅱ-3 with only HKαα/--SEA or HKαα/-α4.2 presented with α-thalassemia minor trait. Ⅰ-1, the carrier of both HKαα/-α3.7 and ß41-42 /ßN , showed a typical ß-thalassemia trait. Fetus with genotype HKαα/-α4.2 alone was not likely to suffer from any deleterious effects after birth. The whole sequence of HKαα allele revealed that HKαα alleles in the six patients shared a high similarity, implying that all HKαα alleles are likely from the same ancestor. Moreover, pedigree and sequencing analyses demonstrated that the HKαα allele contained αααanti4.2 mutation, -α3.7 mutation, and a fragment from α-hemoglobin gene; thus, the composition and formation of HKαα allele was revealed. Finally, the high similarity and composition of HKαα alleles implies that once HKαα formed, αααanti4.2 and -α3.7 mutations tended to be a fusion gene and quite impossible to be inherited separately. CONCLUSION: The two-round nested PCR is an effective method to detect HKαα allele. Besides, our study for the first time revealed the sequence of the HKαα allele, the evidence of the same ancestor with HKαα thalassemia and enriched the composition as well as the formation mechanism of HKαα allele, and immediately opened up novel potential diagnosis and prenatal counseling for HKαα thalassemia.

A Pilot Study of Noninvasive Prenatal Diagnosis of Alpha- and Beta-Thalassemia with Target Capture Sequencing of Cell-Free Fetal DNA in Maternal Blood.

AIMS: Thalassemia is a dangerous hematolytic genetic disease. In south China, ∼24% Chinese carry alpha-thalassemia or beta-thalassemia gene mutations. Given the fact that the invasive sampling procedures can only be performed by professionals in experienced centers, it may increase the risk of miscarriage or infection. Thus, most people are worried about the invasive operation. As such, a noninvasive and accurate prenatal diagnosis is needed for appropriate genetic counseling for families with high risks. Here we sought to develop capture probes and their companion analysis methods for the noninvasive prenatal detection of deletional and nondeletional thalassemia. MATERIALS AND METHODS: Two families diagnosed as carriers of either beta-thalassemia gene or Southeast Asian deletional alpha-thalassemia gene mutation were recruited. The maternal plasma and amniotic fluid were collected for prenatal diagnosis. Probes targeting exons of the genes of interest and the highly heterozygous SNPs within the 1Mb flanking region were designed. The target capture sequencing was performed with plasma DNA from the pregnant woman and genomic DNA from the couples and their children. Then the parental haplotype was constructed by the trios-based strategy. The fetal haplotype was deduced from the parental haplotype with a hidden Markov model-based algorithm. RESULTS: The fetal genotypes were successfully deduced in both families noninvasively. The noninvasively constructed haplotypes of both fetuses were identical to the invasive prenatal diagnosis results with an accuracy rate of 100% in the target region. CONCLUSION: Our study demonstrates that the effective noninvasive prenatal diagnosis of alpha-thalassemia and beta-thalassemia can be achieved with the targeted capture sequencing and the haplotype-assisted analysis method.

Rapid detection of non-deletional mutations causing α-thalassemia by multicolor melting curve analysis.

BACKGROUND: α-Thalassemia, caused by mutations in the α-globin genes, is one of the most common monogenic inherited disorders in the world. However, non-deletional α-thalassemia mutations remain undetected in routine clinical testing due to the lack of a suitable method. In this study, a closed- and single-tube assay for the detection of six common non-deletional α-thalassemia mutations in the HBA2 gene was developed based on multicolor melting curve analysis. METHODS: The assay consisted of one pair of primers specific for the HBA2 gene and four dual-labeled, self-quenched probes targeting six non-deletional α-thalassemia mutations. The sensitivity, reproducibility, and accuracy of the method were validated via 700 genomic DNA samples. RESULTS: The assay had a reproducibility of 100%, could detect gDNA of different genotype as low as 1 ng per reaction, and had an overall accuracy of 100% when compared with RDB analysis and Sanger sequencing. CONCLUSIONS: The developed assay is rapid, robust, and cost-effective while maintaining high sensitivity, specificity, and throughput.

[Paternally originated Wolf-Hirschhorn syndrome detected by multiplex ligation-dependent probe amplification and microarray comparative genomic hybridization].

OBJECTIVE: To confirm the diagnosis of a Wolf-Hirschhorn syndrome by family study using both cytogenetic and molecular genetic techniques. METHOD: G-band karyotyping was performed for all the 6 members in the family. Multiplex ligation-dependent probe amplification (MLPA) was used to detect the chromosome abnormality for the proband, his father and brother. Microarray comparative genomic hybridization (Array-CGH) was carried out to map the exact chromosomal breakpoints for the proband. RESULT: The proband presented with a typical face, delayed growth and hypotonia in Wolf-Hirschhorn syndrome. His G-band karyotype was 46, XY, der(4)t(4;8) (p16.2; p23.1)pat. MLPA showed 4pter loss and 8pter gain. Array-CGH revealed an XY male with a 3.781 Mb deletion of 4p16.3-p16.2 and a 6.760 Mb duplication of 8p23.3-p23.1. The proband's brother has mental retardation and skeletal abnormalities. His G-band karyotype was 46, XY, der(8)t(4;8)(p16.2;p23.1)pat. MLPA showed 4pter gain and 8pter loss. The proband's father had normal phenotype with a balanced translocation of 46, XY, t(4;8)(p16.2;p23.1)pat. MLPA showed a normal result. The proband's grandfather showed a normal phenotype with a balanced translocation 46, XY, t(4;8)(p16.2;p23.1). The other members in the family showed normal phenotypes with normal karyotypes. CONCLUSION: The proband has features of Wolf-Hirschhorn syndrome with partial monosomy 4p and partial trisomy 8p. The proband's brother has a partial trisomy 4p and partial monosomy 8p. The derived chromosomes are inherited from paternal balanced translocation t(4;8)(p16.2;p23.1).

[Hematologic parameters and genotype analysis in 166 children with HbH disease in the North Guangxi region].

OBJECTIVE: To study the characteristics of genotype spectrum and hematologic parameters in children with HbH disease in the North Guangxi region. METHODS: HbH disease was identified by clinical manifestations, routine blood tests and hemoglobin electrophoresis in 166 children who came form the North Guangxi region. Genotypes were determined by Multi-PCR combined with PCR reverse dot blot. DNA sequencing was used when the genotype could not be identified by regular methods. RESULTS: Of the 166 children with HbH disease, 8 genotypes were identified: --SEA/-α3.7 (82 cases), --SEA/-α4.2 (40 cases), --SEA/αCSα (38 cases), --SEA/αQSα (1 case), --SEA/αWSα (1 case), --SEA/αCD43/44 (-C) α (1 case), --SEA/-α3.7 plus CD17 (A→T) (1 case) and --SEA/-α4.2 plus CD41-42(-TTCT) (1 case). One case was confirmed as the heterozygote of --SEA and an unknown mutation. In the 134 cases with complete medical data, 2 had normal hemoglobin levels, 36 manifested mild anemia, 90 manifested moderate anemia, and 6 (genotype: --SEA/αCSα) showed severe anemia because of the coexistence of infection. Children with the genotype of --SEA/-α3.7 (69 cases), --SEA/-α4.2 (31 cases) and --SEA/αCSα (34 cases) had hemoglobin levels of 62-120, 69-127 and 34-110 g/L respectively. The hemoglobin level in the --SEA/αCSα group was significantly lower than in the deletional HbH disease group (genotypes: --SEA/-α3.7 and --SEA/-α4.2 ) (P<0.05). In contrast, MCV levels in the --SEA/αCSα group were significantly higher than in the deletional HbH disease group (P<0.05). CONCLUSIONS: The genotype spectrum of HbH disease is diverse in the North Guangxi region. Deletional genotype is prevalent. The disease is heterogeneous. The children with --SEA/αCSα HbH disease have severer anemia and higher MCV levels than those with deletional HbH disease.

Hemoglobin H disease due to a de novo mutation at the α2-globin gene and an inherited common α-thalassemia deletion found in a Chinese boy.

Hemoglobin (Hb) H disease is a moderate form of α-thalassemia resulting from various genetic defects. A novel frameshift mutation cd 43/44(-C) at the α2-globin gene was identified in a Chinese boy with hemoglobin H disease by sequencing. The proband's mother carries a common α-thalassemia deletion while his father was normal both in the hematological phenotype and α-globin genotype, which suggested that it occurred as a de novo mutation. Molecular studies revealed a compound heterozygote for the Southeast Asian α-thalassemia deletion and this novel spontaneous mutation (-/α(T)α) and the patient exhibited the clinical manifestation of classic hemoglobin H disease. Based on the results of excluding the possibility of a somatic mosaicism of a point mutation in the α2-globin gene, we progress that this de novo single-base deletion should have arisen during the spermatogenic process or earlier embryonic stage. The present study provides information in determining a supplementary model of inheritance for α-thalassemia, which should be useful in genetic counseling.

Detection of alpha-thalassemia in China by using multiplex ligation-dependent probe amplification.

The multiplex ligation-dependent probe amplification (MLPA) method was used to analyze 118 DNA samples from 90 alpha-thalassemia (alpha-thal) patients and 28 normal persons from Southern China, where the main causes of alpha-thal are three large deletions (-alpha3.7, -alpha4.2, and --SEA) and two point mutations in the alpha-globin gene cluster on chromosome 16. The results, detected by the P140B HBA kit, were in complete concordance with the results detected by multiplex polmymerase chain reaction (m-PCR) and real-time PCR. The advantages and limitations of the techniques are discussed. We concluded that MLPA was a rapid and reliable method to determine the cause of both deletional and nondeletional alpha-thal in China.

[A study on the (CA)n in FVIII gene in Han ethnic group in Guangxi Zhuang Autonomous Region by amplification polymorphisms combined with silver staining].

OBJECTIVE: Hemophilia A is an inherited bleeding disorder caused by defects in factor VIII (FVIII) gene. In the present study, the frequencies of the microsatellite alleles at introns 13 and 22 in the factor VIII gene were analyzed in the group of Han nationality in Guangxi Zhuang Autonomous Region to explore their diagnostic value for hemophilia A. These two sites were also used to detect the carriers in 13 hemophilia A families. METHODS: Ninty-one individuals of Han ethnic group in Guangxi Zhuang Autonomous Region (135 X chromosomes) and 13 HA families were subjected to molecular studies. First, these two fragments were PCR amplified simultaneously. Then, silver staining was used later to show their polymorphisms. The investigators selected one sample at random to obtain its lengths of the PCR products at these two sites by ABI310 PCR amplifier. After counting its repeated numbers of (CA) according to the documents concerned, the repeated numbers of the other samples could be counted easily. RESULTS: In the 91 individuals, 6 and 4 alleles were detected at these two sites, respectively. At intron 13 the allele frequencies ranged from 0.0002 to 0.5408 and polymorphism information content (PIC) was 0.5899. At intron 22 the allele frequencies ranged from 0.0444 to 0.4963 and its PIC was 0.5359. The actual heterozygosity for intron 13 and intron 22 were 0.6364 (28/44) and 0.5227 (23/44), respectively. In 13 hemophilia A families with positive history, 9 of them were diagnosed by this method and the diagnosis rate was 69%. CONCLUSION: With high PICs, (CA)n at intron 13 and intron 22 were two valuable sites in the diagnosis of hemophilia A in the population of Han ethnic group in Guangxi Zhuang Autonomous Region. Compared with some other HA restrictive fragment length polymorphisms (RFLP), intron 22 (GT)n (AG)n was more informative.