Mitochondrial disease

Gene: PDE12

Green List (high evidence)

3 families (2 consanguineous) with 5 affected individuals with early onset mitochondrial disease presentation (3 liveborn, 2 intrauterine death).
-Family 1: 1 x infant death @3mths (no clinical information), 1 x 7yr old with neonatal respiratory and lactic acidosis, developmental delay, and mitochondrial respiratory chain deficiencies, and marked cytochrome c oxidase (COX) deficiency in muscle.
-Family 2: 1 x neonatal death @2days with metabolic acidosis and lactic acidosis, respiratory failure, lissencephaly, dysgenesis of the corpus callosum and extensive periventricular and subcortical cysts. Normal pyruvate dehydrogenase complex and electron
transfer chain activities in fibroblasts.
-Family 3: 2 x fetuses (13wks and 22wks) with increase nuchal translucency and reduced fetal movements. One had intra-uterine growth retardation, hydrops and cystic hygroma. The other had permanent flexion contractures of four limbs). Western blotting in fetal skeletal muscle showed absent respiratory chain complexes (I, IV, and V).

WES in all 3 families identified 3 different homozygous missense variants in PDE12 gene (p.Tyr155Cys, p.Gly372Glu, and p.Arg41Pro). All variants segregated with disease, were rare in gnomAD, and in silico pathogenicity prediction tools pointed towards a high likelihood of pathogenicity.

PDE12 gene encodes the poly(A)-specific exoribonuclease, involved in the quality control of mitochondrial non-coding RNAs. Patient-derived primary fibroblasts demonstrate diminished steady-state levels of PDE12 protein, whilst mitochondrial poly(A)-tail RNA sequencing revealed an accumulation of spuriously polyadenylated mitochondrial RNA, consistent with perturbed function of PDE12 protein.
Sources: Literature

Created: 9 Dec 2024, 9:51 p.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Mitochondrial disease MONDO:0044970

Publications

• PMID: 39567835