Abundant decidual natural killer (dNK) cells at the maternal-fetal interface are important during early pregnancy. However, functional subsets of dNK cells remain poorly understood. We describe a CD49a⁺PBX homeobox 1 (PBX1)⁺ dNK cell subset that promotes fetal development in humans and mice. The expression of PBX1 in dNK cells is up-regulated via the activated AKT1 pathway through the interaction of major histocompatibility complex G with the immunoglobulin-like transcript 2 receptor. PBX1 drives pleiotrophin and osteoglycin transcription in dNK cells, further promoting fetal development. Decreased PBX1 expression or the PBX1^G21S mutant correlated with fetal growth restriction and pregnancy failure in patients with unexplained recurrent spontaneous abortion (URSA). Inactivation of Pbx1 in mouse dNK cells impairs fetal development by decreasing growth-promoting factors from CD49a⁺PBX1⁺ dNK cells. Impairment of PBX1 in dNK cells has positive correlation with URSA pathogenesis and may provide a potential marker for this condition.

Duchenne Muscular Dystrophy (DMD) is the most common muscle disease in children, and there are no effective therapies for DMD or Becker Muscular Dystrophy (BMD). Currently, targeted gene therapy treatments have emerged. As a result, genetic diagnosis is the basis of treatment. In addition, genetic and prenatal diagnosis significantly reduces their incidence rates. This study combines the application of multiplex ligation-dependent probe amplification technology (MLPA) and “next-generation” sequencing technology (NGS) as the most economical and efficient method of diagnosis. Therefore, in the diagnosis of DMD/BMD, patients’ MLPA data are first used to detect DMD gene deletions or duplications, and NGS and Sanger sequencing are then applied to exclude MLPA-negative samples. Meanwhile, polymerase chain reaction (PCR) is used to detect single exon deletions to exclude false-positives in MLPA caused by point mutations. In this study, we recruited 1051 proband families of DMD from 2016 to 2018 and had access to information that could identify individual participants during or after data collection. Patients who were diagnosed with DMD were first tested by MLPA. MLPA results with single exon deletions were validated with PCR amplification and Sanger sequencing. The negative results of MLPA were further analysed with NGS and validated by Sanger sequencing. For novel missense mutations, phenotype-genotype correlations were analysed using PolyPhen2 and mutation taster. All methods were performed in accordance with the relevant guidelines and regulations. DMD mutations were identified in 1029 families (97.91%, 1029/1051). Large deletions, duplications, and small mutations accounted for 70.41% (740/1051), 8.28% (87/1051), and 19.12% (201/1051) of all cases, respectively. There were 205 small mutation types, 53 of which were novel. The rate of de novo mutations was 39.45% (187/474) and was higher in large duplications (49.53%, 157/317). Among 68 asymptomatic patients (< 3 years old) with unexplained persistent hyperCKaemia upon conventional physical examination, 63 were diagnosed as DMD/BMD according to genetic diagnosis. Our results expand the spectrum of DMD mutations, which could contribute to the treatment of DMD/BMD and provide an effective diagnosis method. Thus, the combination of MLPA, NGS and Sanger sequencing is of great significance for family analysis, gene diagnosis and gene therapy.

Objective: The aim of this study is to explore the cause of miscarriage, providing risk assessment to guide the next pregnancy. Methods: Four hundred eighty-four products-of-conception (POC) samples were analyzed by single nucleotide polymorphism (SNP) array, and peripheral blood samples of couples were collected for karyotyping or fluorescence in situ hybridization (FISH) analysis. Results: Four hundred sixty-eight of the 484 (96.7%) fresh POC samples were successfully analyzed using SNP-array. The rate of clinically significant chromosomal abnormalities were 58.3% (274/468), in which rates of aneuploidy, polyploidy, partial aneuploidy, uniparental isodisomy (isoUPD), and pathogenic microdeletion/microduplication were 43.4% (203/468), 8.8% (41/468), 3.6% (17/468), 1.9% (9/48), and 0.9% (4/468), respectively. The percentage of embryonic chromosomal abnormalities significantly increased with maternal age of patients older than 35 years old. Among 468 couples, 12 major chromosomal rearrangements were detected by G-banding, including nine reciprocal translocations, two Robertsonian translocations, and one superfemale. Conclusions: Chromosome abnormality is the main causes of early miscarriage, and aneuploidies are the most common type of chromosomal abnormalities. Application of SNP array and karyotyping in early miscarriage can provide more genetic information about miscarriage, providing risk assessment to guide the next pregnancy.

We sought to analyse MMACHC variants among 126 pedigrees with cobalamin (cbl) C deficiency and combined methylmalonic aciduria and homocystinuria by Sanger sequencing, characterize the spectrum of MMACHC gene variants, and perform prenatal genetic diagnosis by chorionic villus sampling among these pedigrees. Peripheral blood was collected from 126 probands and their parents who visited the Genetic Counseling Clinic at our hospital between January 2014 and December 2017, and DNA was extracted from the blood. Then, we amplified the coding sequence and splicing regions of the MMACHC gene by PCR, and the PCR products were further sequenced to detect the variants in each pedigree. In 62 families, pregnant women were subjected to chorionic villus sampling for prenatal genetic diagnosis. In total, 31 distinct variants were detected in the 126 pedigrees, and the most frequent variants were c.609G > A (p.Trp203Ter), c.658_660delAAG (p.Lys220del), c.567dupT (p.Ile190Tyrfs*13) and c.80A > G (p.Gln27Arg). Two of these variants have not been previously reported in the literature. One variant [c.463_465delGGG (p.Gly155del)] is a small-scale deletion, and the other variant [c.637G>T(p.Glu213Ter)] is a nonsense mutation. Among the 62 pedigrees who received a prenatal diagnosis, 16 foetuses were normal, 34 foetuses were carriers of heterozygous variants, and the remaining 12 foetuses harboured compound heterozygous variants or homozygous variants. Couples whose foetuses were normal or carriers continued the pregnancy, whereas couples whose foetuses harboured compound heterozygous variants or homozygous variants decided to terminate the pregnancy. The follow-up results were consistent with the prenatal diagnosis. Two novel MMACHC variants were identified, and prenatal genetic diagnosis is an accurate and convenient method that helps avoid the delivery of combined methylmalonic aciduria and homocystinuria patients.