PUBLICATION

A recessive variant in TFAM causes mtDNA depletion associated with primary ovarian insufficiency, seizures, intellectual disability and hearing loss

Authors
Ullah, F., Rauf, W., Khan, K., Khan, S., Bell, K.M., de Oliveira, V.C., Tariq, M., Bakhshalizadeh, S., Touraine, P., Katsanis, N., Sinclair, A., He, S., Tucker, E.J., Baig, S.M., Davis, E.E.
ID
ZDB-PUB-211015-18
Date
2021
Source
Human genetics   140(12): 1733-1751 (Journal)
Registered Authors
Davis, Erica, Katsanis, Nicholas
Keywords
none
MeSH Terms
  • Animals
  • Cells, Cultured
  • DNA, Mitochondrial*
  • DNA-Binding Proteins/genetics*
  • Female
  • Genes, Recessive*
  • Gonads/embryology
  • Hearing Loss/genetics*
  • Humans
  • Intellectual Disability/genetics*
  • Male
  • Mitochondrial Proteins/genetics*
  • Pedigree
  • Primary Ovarian Insufficiency/genetics*
  • Seizures/genetics*
  • Transcription Factors/genetics*
  • Zebrafish/genetics
PubMed
34647195 Full text @ Hum. Genet.
Abstract
Mitochondrial disorders are collectively common, genetically heterogeneous disorders in both pediatric and adult populations. They are caused by molecular defects in oxidative phosphorylation, failure of essential bioenergetic supply to mitochondria, and apoptosis. Here, we present three affected individuals from a consanguineous family of Pakistani origin with variable seizures and intellectual disability. Both females display primary ovarian insufficiency (POI), while the male shows abnormal sex hormone levels. We performed whole exome sequencing and identified a recessive missense variant c.694C > T, p.Arg232Cys in TFAM that segregates with disease. TFAM (mitochondrial transcription factor A) is a component of the mitochondrial replisome machinery that maintains mtDNA transcription and replication. In primary dermal fibroblasts, we show depletion of mtDNA and significantly altered mitochondrial function and morphology. Moreover, we observed reduced nucleoid numbers with significant changes in nucleoid size or shape in fibroblasts from an affected individual compared to controls. We also investigated the effect of tfam impairment in zebrafish; homozygous tfam mutants carrying an in-frame c.141_149 deletion recapitulate the mtDNA depletion and ovarian dysgenesis phenotypes observed in affected humans. Together, our genetic and functional data confirm that TFAM plays a pivotal role in gonad development and expands the repertoire of mitochondrial disease phenotypes.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping