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MELAS syndrome involving a mother and two children
Abstract:
Three familial cases of MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke) have been reported. We describe a family with four normal sons and an affected mother, son, and daughter. Although mitochondrial inheritance has been proposed, autosomal and X-linked dominant patterns are also possible. This family also illustrates the variability of expression of MELAS. The proband has the full syndrome, while the mother and daughter manifested less severe findings. All three did not develop symptoms until adulthood.
Insights
This study details a family with Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke (MELAS), showing varied inheritance patterns and symptom severity. The findings highlight the complex genetic and clinical presentation of MELAS across generations.
Area of Science:
- Genetics
- Neurology
- Mitochondrial Diseases
Background:
- Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke (MELAS) is a rare genetic disorder.
- Familial cases of MELAS are infrequently reported, making genetic analysis challenging.
Observation:
- A family presented with four unaffected sons and an affected mother, son, and daughter.
- The proband exhibited the full MELAS syndrome, while the mother and daughter showed milder, variable symptoms.
- All affected individuals developed symptoms in adulthood, indicating late-onset presentation.
Findings:
- The observed inheritance pattern in this family is inconsistent with simple mitochondrial inheritance, suggesting autosomal or X-linked dominant transmission as possibilities.
- The variable expressivity of MELAS was evident, with differing symptom severity among affected family members.
- Late-onset MELAS presentation was observed in all affected individuals.
Implications:
- This case underscores the need to consider diverse inheritance models beyond mitochondrial transmission for MELAS.
- Understanding MELAS variability is crucial for accurate diagnosis and genetic counseling.
- Further research into the genetic factors influencing MELAS expression and onset is warranted.