Dataset Information

Two novel mutations in the KHDC3L gene in Asian patients with recurrent hydatidiform mole.

ABSTRACT: Recurrent hydatidiform mole (RHM) is defined by the occurrence of repeated molar pregnancies in affected women. Two genes, NLRP7 and KHDC3L, play a causal role in RHM and are responsible for 48-80% and 5% of cases, respectively. Here, we report the results of screening these two genes for mutations in one Iranian and one Indian patient with RHM. No mutations in NLRP7 were identified in the two patients. KHDC3L sequencing identified two novel protein-truncating mutations in a homozygous state, a 4-bp deletion, c.17_20delGGTT (p.Arg6Leufs*7), in the Iranian patient and a splice mutation, c.349+1G>A, that affects the invariant donor site at the junction of exon 2 and intron 2 in the Indian patient. To date, only four mutations in KHDC3L have been reported. The identification of two additional mutations provides further evidence for the important role of KHDC3L in the pathophysiology of RHM and increases the diversity of mutations described in Asian populations.

SUBMITTER: Rezaei M

PROVIDER: S-EPMC5007383 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Two novel mutations in the KHDC3L gene in Asian patients with recurrent hydatidiform mole.

Rezaei Maryam M Nguyen Ngoc Minh Phuong NM Foroughinia Leila L Dash Pratima P Ahmadpour Fatemeh F Verma Ishwar Chandra IC Slim Rima R Fardaei Majid M

Human genome variation 20160901

Recurrent hydatidiform mole (RHM) is defined by the occurrence of repeated molar pregnancies in affected women. Two genes, NLRP7 and KHDC3L, play a causal role in RHM and are responsible for 48-80% and 5% of cases, respectively. Here, we report the results of screening these two genes for mutations in one Iranian and one Indian patient with RHM. No mutations in NLRP7 were identified in the two patients. KHDC3L sequencing identified two novel protein-truncating mutations in a homozygous state, a ...[more]

PMID: 27621838

Similar Datasets

Project description:BACKGROUND:Maternal effect mutations in the components of the subcortical maternal complex (SCMC) of the human oocyte can cause early embryonic failure, gestational abnormalities and recurrent pregnancy loss. Enigmatically, they are also associated with DNA methylation abnormalities at imprinted genes in conceptuses: in the devastating gestational abnormality biparental complete hydatidiform mole (BiCHM) or in multi-locus imprinting disease (MLID). However, the developmental timing, genomic extent and mechanistic basis of these imprinting defects are unknown. The rarity of these disorders and the possibility that methylation defects originate in oocytes have made these questions very challenging to address. METHODS:Single-cell bisulphite sequencing (scBS-seq) was used to assess methylation in oocytes from a patient with BiCHM identified to be homozygous for an inactivating mutation in the human SCMC component KHDC3L. Genome-wide methylation analysis of a preimplantation embryo and molar tissue from the same patient was also performed. RESULTS:High-coverage scBS-seq libraries were obtained from five KHDC3Lc.1A>G oocytes, which revealed a genome-wide deficit of DNA methylation compared with normal human oocytes. Importantly, germline differentially methylated regions (gDMRs) of imprinted genes were affected similarly to other sequence features that normally become methylated in oocytes, indicating no selectivity towards imprinted genes. A range of methylation losses was observed across genomic features, including gDMRs, indicating variable sensitivity to defects in the SCMC. Genome-wide analysis of a pre-implantation embryo and molar tissue from the same patient showed that following fertilisation methylation defects at imprinted genes persist, while most non-imprinted regions of the genome recover near-normal methylation post-implantation. CONCLUSIONS:We show for the first time that the integrity of the SCMC is essential for de novo methylation in the female germline. These findings have important implications for understanding the role of the SCMC in DNA methylation and for the origin of imprinting defects, for counselling affected families, and will help inform future therapeutic approaches.

Project description:A genomic clone containing two linked human pregnancy-specific beta 1-glycoprotein (PS beta G) genes has been isolated and characterized. The two genes are arranged in the same 5'----3' orientation; the 3' region (including the A2 and B-C exons) of the upstream gene, PSGGA, is linked to the 5' region (including the 5'/L and L/N exons) of PSGGB, the downstream gene. Depending upon the domains compared, PSGGA and PSGGB share 92-98% nucleotide and 86-95% amino acid sequence identity with PSG93, the most abundant PS beta G transcript. The 3' exon (B-C) of PSGGA contains four alternative splice sites and three polyadenylylation sites, which account for the 3' heterogeneity previously reported in the PS beta G family. Each of the predicted PSGGA-encoded proteins would have a different carboxyl terminus. PSGGB corresponds to the previously identified cDNA PSG6, which encodes proteins containing a 34-amino acid leader peptide and a 108-amino acid N domain, which is one amino acid shorter than the majority of PS beta G N domains. Additionally, the PSGGB-encoded proteins contain the cell-surface recognition tripeptide Arg-Gly-Asp, shared by several previously reported PS beta Gs as deduced from cDNA sequences. Northern blot hybridization performed with a PSGGB-specific oligonucleotide probe to the N domain revealed that PSGGB or a PSGGB-like gene encodes a major 1.7-kilobase mRNA in hydatidiform mole tissues and a major 2.0-kilobase mRNA in term placenta tissues. Moreover, the PSGGB-specific probe hybridized most strongly with mRNA from molar trophoblastic tissue, suggesting that the PSGGB-like species may be the gene preferentially expressed in gestational trophoblastic disease. Additionally, the sequence of a 2315-base-pair PS beta G cDNA (PSG95) that contains an N-A1-A2-B2-C domain arrangement is reported. The coding region of PSG95 is identical to the previously reported cDNA clones PSG1d and FL-NCA, but PSG95 contains an additional 518 and 523 base pairs in the 3' end as compared with PSG1d and FL-NCA, respectively.

Dataset Information

Two novel mutations in the KHDC3L gene in Asian patients with recurrent hydatidiform mole.

Publications

Two novel mutations in the KHDC3L gene in Asian patients with recurrent hydatidiform mole.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets