Holocarboxylase synthetase is an important mitochondrial enzyme for processing dietary biotin. An hereditary defect in the enzyme impacts gluconeogenesis, amino acid catabolism and fatty acid synthesis.
Inheritance: autosomal recessive (may have affected siblings)
Onset: early onset, from birth to 21 months of age, with most presenting before 3 months of age
Common metabolic findings (present in all or most patients):
(1) metabolic acidosis (ketolactic acidosis)
(2) organic aciduria
(3) hyperammonemia
Respiratory findings:
(1) tachypnea
(2) hyperventilation
Neurologic findings:
(1) lethargy
(2) irritability
(3) abnormal muscle tone (hyper or hypotonia)
(4) seizures
(5) abnormal reflexes (hyper or hyporeflexia)
(6) developmental delay
(7) ataxia
(8) tremor
(9) coma
Skin changes:
(1) skin rash
(2) alopecia
Other findings:
(1) odor of urine
(2) thrombocytopenia
(3) feeding problems
(4) vomiting
(5) hypothermia
To read more or access our algorithms and calculators, please log in or register.
