Exome-based preconception carrier testing for consanguineous couples in China.

Objective: To evaluate the utility of clinical exome sequencing (ES)-based carrier screening in Chinese consanguineous couples.

Methods: Consanguineous couples were screened for autosomal recessive (AR) disorders using the clinical ES of 5000 genes associated with human diseases.

Results: We recruited 14 couples who elected to have sequencing.

Tetrasomy 18p Case Report.

Background: Tetrasomy 18p is a rare disorder. It is known to affect about 250 families worldwide. Tetrasomy 18p is also the most common type of isochromosome.

Molecular and Hematological Characterization of a Novel Translation Initiation Codon Mutation of the α2-Globin Gene (AT>AT or : c.3G>C).

Although mutations causing α-thalassemia (α-thal) are mainly larger deletions involving one or both of the duplicated α-globin genes, point mutations are not rare. We have identified a novel mutation of the translation initiation codon of the α2-globin gene with DNA sequencing and allele-specific multiplex ligation-dependent probe amplification (MLPA) in a Chinese family. RNA analysis was performed with reverse transcription-MLPA (RT-MLPA).

Can cell-free DNA testing be used in pregnancies with isolated fetal omphalocele? Preliminary evidence from cytogenetic results of prenatal cases.

To evaluate whether cell-free DNA (cfDNA) testing could replace an invasive procedure in pregnancies with isolated fetal omphalocele. This was a retrospective study of all pregnancies with sonographically detected fetal omphalocele at three tertiary referral centers between 2012 and 2016. Invasive diagnostic testing was performed for genetic investigations using conventional karyotyping or chromosomal microarray.

Fetal Anemia and Hydrops Fetalis Associated with Homozygous Hb Constant Spring (HBA2: c.427T > C).

Hb Constant Spring (Hb CS, HBA2: c.427T > C) is a common nondeletional α-thalassemia (α-thal) that results from a nucleotide substitution at the termination codon of the α2-globin gene. Homozygosity for Hb CS (α(CS)α/α(CS)α) is relatively rare, and generally characterized with mild hemolytic anemia, jaundice, and splenomegaly.

Prevalence and molecular characterization of structural hemoglobin variants in the Dongguan region of Guangdong province, southern China.

The aim of the present study was to find the most prevalent structural hemoglobin (Hb) variants in southern China and to present hematological and molecular data of abnormal Hbs in the population from southern China. The type and frequency of structural Hb variants and their hematological and molecular characteristics were identified in 131 individuals from 30,848 unrelated partners who were referred to the prenatal clinic of Dongguan Maternal & Children Health Hospital, Dongguan, Guangdong, People's Republic of China (PRC) from 2011 to 2013. α-Globin or β-globin chain variants were screened using a capillary electrophoresis (CE) system, and α-globin or β-globin gene mutations were confirmed using sequencing techniques.

Delineation of the molecular basis of borderline hemoglobin A2 in Chinese individuals.

Background: The "gray zone" of borderline hemoglobin A2 (Hb A2) may be present in a large section of the population, especially in countries where thalassemia is common. However, very little is currently known of the molecular basis of borderline Hb A2 in Chinese individuals.

Method: In this study, we performed a comprehensive analysis of the globin genotypes and KLF1 gene mutations associated with borderline Hb A2 in 165 Chinese subjects.

Screening and diagnosis of Hb Quong Sze [HBA2: c.377T > C (or HBA1)] in a prenatal control program for thalassemia.

Hb Quong Sze [Hb QS, HBA2: c.377T > C (or HBA1)] is a common nondeletional thalassemia in southern China. It is one of the major alleles causing nondeletional Hb H (β4) disease in the Chinese population.

Detection of Hb anti-Lepore Hong Kong (NG_000007.3: g.63154_70565dup) in Chinese individuals.

We have identified four Chinese individuals from three unrelated families with raised Hb A2 levels. The anti-Lepore hybrid hemoglobin (Hb) variant was amplified using a pair of primers, 5' to the β-globin gene Cap site and 3' to the δ-globin gene polyadenylation site (polyA) region, respectively. Direct sequencing of the βδ fusion products confirmed the anti-Lepore Hong Kong (NG_000007.

[Analysis of clinical phenotypes of compound heterozygotes of Hb J-Bangkok and β-thalassemia].

Objective: To analyze hematological characteristics of compound heterozygotes of Hb J-Bangkok and β-thalassemia, and to explore the influence of Hb J-Bangkok on the phenotype of β-thalassemia.

Methods: Peripheral blood samples from a patient carrying Hb J-Bangkok and a β-thalassemia mutation, her family members and three sporadic Hb J-Bangkok carriers were collected. RBC analysis and hemoglobin electrophoresis were performed.

[Analysis of hematological characteristics on the 79 co-inheritance of α-thalassemia and β-thalassemia carriers in Guangxi].

Objective: To investigate the hematological characteristics of co-inheritance of α-thalassemia (α-thal) and β-thalassemia (β-thal) and to survey the incidence of co-inheritance of α-thal and β-thal in Guangxi.

Methods: DNA samples from 370 primary and middle school students who were β-thal carriers in Guangxi were further processed for the α-goblin gene mutation screening, and were grouped based on the genotype of β- and α-goblin gene. The hematological indexes to the different groups were compared by One-way ANOVA.

[Analysis of the phenotype-genotype relationship of Hb Constant Spring].

Objective: To analyze the genotype-phenotype correlations in the Hb Constant Spring (HbCS) carriers, and to investigate the effect of HbCS on hematologic parameters.

Methods: Complete blood cell count and hemoglobin electrophoresis analyses were performed in 125 HbCS cases. The α-and β-thalassemia mutations were determined by reverse dot-blotting and Gap-PCR.

Identification of the linkage of a 1.357 KB beta-globin gene deletion and A gamma-globin gene triplication in a Chinese family.

The 1.357 kb beta-globin gene deletion was identified in a Chinese family by multiplex ligation-dependent probe amplification (MLPA) followed by gap-polymerase chain reaction (gap-PCR) and sequencing. Interestingly, this form of the deletion was linked to a -(G)gamma-(AG)gamma-(A)gamma triplication.