Related Experiment Videos
Carbonic anhydrase II deficiency in three unrelated Japanese patients
S Aramaki1, I Yoshida, M Yoshino
1Department of Pediatrics and Child Health, Kurume University School of Medicine, Japan.
Insights
This study details three Japanese patients with carbonic anhydrase II (CAII) deficiency, a rare genetic disorder. The findings highlight the severe symptoms and genetic basis of CAII deficiency in this population.
Area of Science:
- Biochemistry
- Genetics
- Pediatrics
Background:
- Carbonic anhydrase II (CAII) deficiency is a rare genetic disorder.
- It is inherited in an autosomal recessive pattern.
- CAII plays a crucial role in various physiological processes.
Observation:
- Three unrelated Japanese families presented with CAII deficiency.
- Patients exhibited renal tubular acidosis, osteopetrosis, cerebral calcification, and developmental delays.
- Symptoms ranged from neonatal feeding issues to psychomotor retardation and muscle weakness.
Findings:
- All affected individuals showed deficient CAII enzyme activity and protein levels in red blood cells.
- Carrier parents displayed approximately 50% of normal CAII levels, confirming autosomal recessive inheritance.
- This is the first report of CAII deficiency in the Japanese population.
Implications:
- This study expands the known geographical distribution of CAII deficiency.
- It underscores the importance of early diagnosis and genetic counseling for affected families.
- Further research into CAII function and therapeutic strategies is warranted.
Abstract:
Three Japanese patients with carbonic anhydrase II (CAII) deficiency from three families were described. The parents of one patient were unrelated, the parents of each of the other two patients were first cousins. All the patients had renal tubular acidosis, osteopetrosis, symmetrical cerebral calcification and mental retardation. They exhibited poor activity and poor appetite in the neonatal period, and then developed psychomotor retardation. Two of them were diagnosed as having osteopetrosis at 10 months and 36 years of age, respectively, and the other as having osteomalacia at 28 years of age. All patients had recurrent episodes of muscle weakness. The CAII enzyme activity and protein levels in red blood cells in each of the three patients were deficient. Their parents exhibited approximately 50% normal levels of CAII activity and protein. This is the first report of patients with CAII deficiency in the Japanese population.