Mitochondrial disease
Gene: APOO
PMID: 37649161
1 family, 2 individuals (male & female) with same NMD variant c.532G>T (p.E178*), maternally inherited (mother unaffected).
Both died before 18 months of age with partial agenesis of the corpus callosum, bilateral congenital cataract, hypothyroidism, and severe immune deficiencies.
Other phenotypes included partial syndactyly of the 2nd and 3rd toes, wrinkled palm, and sole skin.
Functional studies included site directed mutagenesis. This mutation resulted in a highly unstable and degradation
prone MIC26 protein, yet the remaining minute amounts of mutant MIC26 correctly localized to mitochondria and
interacted physically with other MICOS subunits. MIC26 KO cells expressing MIC26 harboring the respective APOO/MIC26 mutation showed mitochondria with perturbed cristae architecture and fragmented morphology resembling MIC26 KO cells.Created: 7 Sep 2023, 2:54 a.m. | Last Modified: 7 Sep 2023, 2:54 a.m.
Panel Version: 0.889
Mode of inheritance
X-LINKED: hemizygous mutation in males, biallelic mutations in females
Phenotypes
agenesis of the corpus callosum; bilateral congenital cataract; hypothyroidism; severe immune deficiencies
Publications
- PMID: 32439808 (2021) - Three generation family with c.350T>C variant in APOO, encoding a component of the MICOS complex which plays a role in maintaining inner mitochondrial membrane architecture.
Phenotypes include fatigue and muscle weakness (6/8), learning difficulties and cognitive impairment (4/8), and increased blood lactate (2/8). Four individuals were asymptomatic carriers, including one male (authors indicate variability in female carriers was due to skewed X-inactivation, although skewing studies were inconclusive in some cases). Variability in clinical presentation suggests reduced penetrance or possible contribution of additional factors.
Functional studies showed altered MICOS assembly and abnormalities in mitochondria ultrastructure in patient-derived fibroblasts. Knockdown studies in Drosophila and yeast demonstrated mitochondrial structural and functional deficiencies.
Sources: LiteratureCreated: 3 Mar 2021, 2:09 a.m.
Mode of inheritance
X-LINKED: hemizygous mutation in males, biallelic mutations in females
Phenotypes
Mitochondrial disease, MONDO:0044970, APOO-related; Developmental delay; Lactic acidosis; Muscle weakness; Hypotonia; Repetitive infections; Cognitive impairment; Autistic behaviour
Publications
- PMID: 32439808 (2021) - Three generation family with c.350T>C variant in APOO, encoding a component of the MICOS complex which plays a role in maintaining inner mitochondrial membrane architecture.
Phenotypes include fatigue and muscle weakness (6/8), learning difficulties and cognitive impairment (4/8), and increased blood lactate (2/8). Four individuals were asymptomatic carriers, including one male (authors indicate variability in female carriers was due to skewed X-inactivation, although skewing studies were inconclusive in some cases). Variability in clinical presentation suggests reduced penetrance or possible contribution of additional factors.
Functional studies showed altered MICOS assembly and abnormalities in mitochondria ultrastructure in patient-derived fibroblasts. Knockdown studies in Drosophila and yeast demonstrated mitochondrial structural and functional deficiencies.
Sources: LiteratureCreated: 2 Mar 2021, 3:32 p.m.
Mode of inheritance
X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)
Phenotypes
Developmental delay; Lactic acidosis; Muscle weakness; Hypotonia; Repetitive infections; Cognitive impairment; Autistic behaviour
Publications
Phenotypes for gene: APOO were changed from Developmental delay; Lactic acidosis; Muscle weakness; Hypotonia; Repetitive infections; Cognitive impairment; Autistic behaviour to Mitochondrial disease, MONDO:0044970, APOO-related; Developmental delay; Lactic acidosis; Muscle weakness; Hypotonia; Repetitive infections; Cognitive impairment; Autistic behaviour
Publications for gene: APOO were set to 32439808
Gene: apoo has been classified as Amber List (Moderate Evidence).
Gene: apoo has been classified as Amber List (Moderate Evidence).
gene: APOO was added gene: APOO was added to Mitochondrial disease. Sources: Literature Mode of inheritance for gene: APOO was set to X-LINKED: hemizygous mutation in males, biallelic mutations in females Publications for gene: APOO were set to 32439808 Phenotypes for gene: APOO were set to Developmental delay; Lactic acidosis; Muscle weakness; Hypotonia; Repetitive infections; Cognitive impairment; Autistic behaviour Review for gene: APOO was set to AMBER