Clinical Guidance
3-Hydroxyisobutyryl-CoA hydrolase (HIBCH) deficiency presents with a wide spectrum of clinical features. HIBCH deficiency can be categorized into three subtypes based on age of presentation. Neonatal onset, the least frequent phenotype, is characterized by hypotonia, seizures, and feeding difficulties at birth. There is a high risk of death in childhood, and individuals that survive typically have developmental delay, seizures, poor weight gain, and growth deficiency and develop a movement disorder. Infantile onset is the most common phenotype, presenting in the first two years of life with feeding difficulties, vomiting, developmental delay with regression, hypotonia, seizures, movement disorder, microcephaly, vision impairment, and episodes of neurologic deterioration. Late onset is the second most common phenotype, presenting in childhood as a slowly progressive disease with significant movement disorder with or without paroxysmal dystonia, variable cognitive impairment, and high survivability. To date, 62 individuals have been identified with HIBCH deficiency [, , , , , , , , , , , , , , , , , , , , , , , , , , , , ]. The following description of the phenotypic features associated with this condition is based on these reports. Table 2. 3-Hydroxyisobutyryl-CoA Hydrolase Deficiency: Frequency of Select Features
Feature | Age of Onset | All Ages of Onset4,5(n=62) | |
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