HADHB (beta-hydroxyacyl-CoA dehydrogenase) gene mutations result in a variety of clinical features collectively known as mitochondrial trifunctional protein (MTP) deficiency. This autosomal recessive disorder can present in infancy or childhood with a range of symptoms that can be divided into three main categories: 1) early cardiomyopathy-metabolic disorder, 2) hepatic or 3) muscular-neuropathy.
• Early onset cardiomyopathy and metabolic disorder: Neonates with the severe phenotype present within a few days of birth with hypoglycemia, hepatomegaly, encephalopathy, and a cardiomyopathy.
• The intermediate phenotype is characterized by hypoketotic hypoglycemia exacerbated by infection or fasting in infancy.
• The mild (late-onset) phenotype is characterized by myopathy and/or neuropathy resembling axonal Charcot-Marie-Tooth disease
In addition to these main clinical features, individuals with HADHB mutations may also exhibit other neurological symptoms such as developmental delay and seizures.
Presence of carnitylated-long chain fatty acids in blood analysis is frequent. MTP deficiency is an ultra rare disorder difficult to assess because of the variety of phenotypes (40 mutations reported so far).
HADHB