ABSTRACT
OBJECTIVE@#To explore the genetic basis for a fetus with limb abnormality and cardiac malformation.@*METHODS@#Clinical data of a fetus diagnosed at the Shandong Provincial Maternal and Child Health Care Hospital on April 30th, 2021 was collected. Whole exome sequencing (WES) was carried out, and candidate variant was verified by Sanger sequencing and bioinformatic analysis. X-inactivation analysis was carried out for the female members of its family.@*RESULTS@#The fetus was found to have meningoencephalocele, absence of bilateral radii, cleft lip, abnormal great arteries, and single umbilical artery at the gestational age of 11+ weeks. Sequencing revealed that the fetus has harbored a hemizygous c.1162del (p.Y388Tfs*7) variant of the FANCB gene, which was maternally inherited. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG) and ClinGen, the variant was classified as pathogenic (PVS1+PM2_Supporting+PP4). X-inactivation analysis has revealed complete skewed X-inactivation in the pregnant woman and her mother.@*CONCLUSION@#The hemizygous c.1162del (p.Y388Tfs*7) variant of the FANCB gene probably underlay the multiple malformations in this fetus.
Subject(s)
Female , Humans , Pregnancy , Abnormalities, Multiple , Cleft Lip , Fanconi Anemia Complementation Group Proteins , Fetus , Gestational Age , MothersABSTRACT
Fanconi anemia (FA) is an autosomal or X-linked recessive disorder characterized by chromosomal instability, bone marrow failure, cancer susceptibility, and a profound sensitivity to agents that produce DNA interstrand cross-link (ICL). To date, 15 genes have been identified that, when mutated, result in FA or an FA-like syndrome. It is believed that cellular resistance to DNA interstrand cross-linking agents requires all 15 FA or FA-like proteins. Here, we review our current understanding of how these FA proteins participate in ICL repair and discuss the molecular mechanisms that regulate the FA pathway to maintain genome stability.
Subject(s)
Humans , DNA Damage , DNA Repair , Exodeoxyribonucleases , Genetics , Metabolism , Fanconi Anemia , Genetics , Metabolism , Pathology , Fanconi Anemia Complementation Group N Protein , Fanconi Anemia Complementation Group Proteins , Genetics , Metabolism , Nuclear Proteins , Genetics , Metabolism , Recombinases , Genetics , Metabolism , Tumor Suppressor Proteins , Genetics , Metabolism , UbiquitinationABSTRACT
Fanconi anaemia (FA) is an autosomal recessive inherited disorder caused by defects in hematopoietic stem cells. The clinical manifestations of FA are diverse and complicated. FA cells display high hypersensitivity to agents which produce interstrand DNA cross-links such as mitomycin C (MMC) or diepoxybutane (DEB). At least eight complementation groups with defects in eight genes (FANCA, FANCB, FANCC, FANCD(1), FANCD(2), FANCE, FANCF and FANCG) have been identified by gene analysis. Six genes (corresponding to subtypes A, C, D(2), E, F and G) have been coloned, and the encoded FA proteins interact in a common cellular pathway - "FA Pathway", through which modulate DNA repair. The progress of research on FA molecular mechanism provides gene therapy of FA with theory basis. FA cells transduced with the use of retrovirus carring the normal FA gene cDNA manifestate phenotypic correction of hypersensitivity to DNA cross-linking agents, such as MMC. In this review the clinical manifestations and gene composition of FA, and the functions of encoded FA proteins were summarized. The hematopoietic stem cell transplantation and gene therapy for FA patients were discussed.