De Novo Mutation Causes Fanconi Anemia
By LabMedica International staff writers Posted on 10 Jan 2016 |
Fanconi anemia is clinically typified by susceptibility to bone marrow failure, leukemia, different types of solid tumors, and a strongly reduced life expectancy of the affected persons.
Fanconi anemia (FA) is a rare recessive genetically heterogeneous chromosomal instability disorder with both autosomal and X-linked inheritance and all reported cases so far have displayed a recessive mode of inheritance. FA is characterized by multiple congenital abnormalities, hematological defects and a high predisposition to a diversity of cancers, including childhood acute myeloid leukemia and head and neck cancers.
An international team of scientists led by those at the Institute for Systems Biology (Seattle, WA, USA) used advanced whole genome sequencing as well as other cell and molecular biology techniques. Genomic DNA was isolated from lymphoblastoid cell lines of the patient, the healthy sibling and the parents and whole genomic sequencing performed. Mutation confirmation by Sanger sequencing was done by direct sequencing of polymerase chain reaction (PCR) products.
Samples were analyzed with an ABI 3730 DNA analyzer (Applied Biosystems; Foster City, CA, USA). Other techniques used included cell cultures and transformations, growth inhibition analysis, cell viability assays, protein analysis, protein expression and purification, and cell cycle analysis which were performed subsequently by flow cytometry using a Particle Analyzing System (PAS, Partec; Görlitz, Germany). D-loop formation, ATPase, DNA-binding assays were also carried out. Scanning force microscopy images were obtained on a NanoScope IIIa (Digital Instruments; Santa Barbara, CA, USA).
The scientists found a de novo g.41022153G>A; p.Ala293Thr (NM_002875) missense mutation in one allele of the homologous recombination DNA repair gene RAD51 in an FA-like patient. This heterozygous mutation causes a novel FA subtype, “FA-R,” which appears to be the first subtype of FA caused by a dominant-negative mutation. The patient, who features microcephaly and mental retardation, has reached adulthood without the typical bone marrow failure and pediatric cancers.
Patrick May, PhD, a coauthor of the study, said, “The particular mutation in this patient was a surprise to us. It occurred only in one of the two RAD51 gene copies, which every person carries in the genome, but every RAD51 gene copy was normal in the child´s parents. In consequence the protein with the altered amino acid sequence due to the mutation interfered with the activity of the normal protein. These are the reasons why the child is affected by Fanconi Anemia although his or her relatives are not carrier of the mutation.” The study was published on December 18, 2015, in the journal Nature Communications.
Related Links:
Institute for Systems Biology
Applied Biosystems
Partec
Fanconi anemia (FA) is a rare recessive genetically heterogeneous chromosomal instability disorder with both autosomal and X-linked inheritance and all reported cases so far have displayed a recessive mode of inheritance. FA is characterized by multiple congenital abnormalities, hematological defects and a high predisposition to a diversity of cancers, including childhood acute myeloid leukemia and head and neck cancers.
An international team of scientists led by those at the Institute for Systems Biology (Seattle, WA, USA) used advanced whole genome sequencing as well as other cell and molecular biology techniques. Genomic DNA was isolated from lymphoblastoid cell lines of the patient, the healthy sibling and the parents and whole genomic sequencing performed. Mutation confirmation by Sanger sequencing was done by direct sequencing of polymerase chain reaction (PCR) products.
Samples were analyzed with an ABI 3730 DNA analyzer (Applied Biosystems; Foster City, CA, USA). Other techniques used included cell cultures and transformations, growth inhibition analysis, cell viability assays, protein analysis, protein expression and purification, and cell cycle analysis which were performed subsequently by flow cytometry using a Particle Analyzing System (PAS, Partec; Görlitz, Germany). D-loop formation, ATPase, DNA-binding assays were also carried out. Scanning force microscopy images were obtained on a NanoScope IIIa (Digital Instruments; Santa Barbara, CA, USA).
The scientists found a de novo g.41022153G>A; p.Ala293Thr (NM_002875) missense mutation in one allele of the homologous recombination DNA repair gene RAD51 in an FA-like patient. This heterozygous mutation causes a novel FA subtype, “FA-R,” which appears to be the first subtype of FA caused by a dominant-negative mutation. The patient, who features microcephaly and mental retardation, has reached adulthood without the typical bone marrow failure and pediatric cancers.
Patrick May, PhD, a coauthor of the study, said, “The particular mutation in this patient was a surprise to us. It occurred only in one of the two RAD51 gene copies, which every person carries in the genome, but every RAD51 gene copy was normal in the child´s parents. In consequence the protein with the altered amino acid sequence due to the mutation interfered with the activity of the normal protein. These are the reasons why the child is affected by Fanconi Anemia although his or her relatives are not carrier of the mutation.” The study was published on December 18, 2015, in the journal Nature Communications.
Related Links:
Institute for Systems Biology
Applied Biosystems
Partec
Read the full article by registering today, it's FREE!
Register now for FREE to LabMedica.com and get complete access to news and events that shape the world of Clinical Laboratory Medicine.
- Free digital version edition of LabMedica International sent by email on regular basis
- Free print version of LabMedica International magazine (available only outside USA and Canada).
- Free and unlimited access to back issues of LabMedica International in digital format
- Free LabMedica International Newsletter sent every week containing the latest news
- Free breaking news sent via email
- Free access to Events Calendar
- Free access to LinkXpress new product services
- REGISTRATION IS FREE AND EASY!
Sign in: Registered website members
Sign in: Registered magazine subscribers
Latest Molecular Diagnostics News
- Blood Proteins Could Warn of Cancer Seven Years before Diagnosis
- New DNA Origami Technique to Advance Disease Diagnosis
- Ultrasound-Aided Blood Testing Detects Cancer Biomarkers from Cells
- New Respiratory Syndromic Testing Panel Provides Fast and Accurate Results
- New Synthetic Biomarker Technology Differentiates Between Prior Zika and Dengue Infections
- Novel Biomarkers to Improve Diagnosis of Renal Cell Carcinoma Subtypes
- RNA-Powered Molecular Test to Help Combat Early-Age Onset Colorectal Cancer
- Advanced Blood Test to Spot Alzheimer's Before Progression to Dementia
- Multi-Omic Noninvasive Urine-Based DNA Test to Improve Bladder Cancer Detection
- First of Its Kind NGS Assay for Precise Detection of BCR::ABL1 Fusion Gene to Enable Personalized Leukemia Treatment
- Urine Test to Revolutionize Lyme Disease Testing
- Simple Blood Test Could Enable First Quantitative Assessments for Future Cerebrovascular Disease
- New Genetic Testing Procedure Combined With Ultrasound Detects High Cardiovascular Risk
- Blood Samples Enhance B-Cell Lymphoma Diagnostics and Prognosis
- Blood Test Predicts Knee Osteoarthritis Eight Years Before Signs Appears On X-Rays
- Blood Test Accurately Predicts Lung Cancer Risk and Reduces Need for Scans