Browsing Pathways

3-hydroxyacyl-CoA dehydrogenase deficiency, also known as HADH deficiency or formerly SCHAD deficiency, is a rare inborn error of metabolism (IEM) and autosomal recessive disorder of the mitochondrial beta-oxidation of short chain saturated fatty acid pathway. It is caused by a mutation in the HADH gene which encodes the mitochondrial enzyme hydroxyacyl-coenzyme A dehydrogenase. This enzyme is responsible for the beta-oxidation of 3-hydroxyhexanoyl-CoA and 3-hydroxybutyryl-CoA into 3-oxohexanoyl-CoA and acetoacetyl-CoA respectively. Symptoms of HADH deficiency include hypoglycemia, as well as vomiting, diarrhea and seizures. Treatment with diazoxide, a potassium channel activator, has been effective. It is estimated that HADH deficiency affects less than 1 in 1,000,000 individuals.

Joubert syndrome is a condition in which brain development is not completed as it should be, including the lack or underdevelopment of the part of the brain that regulates balance and coordination and an abnormal brain stem. The symptoms affect a variety of body parts in the patient, including apnea, ataxia brought on by hypotonia, abnormal eye movements and intellectual disability. Many different gene mutations are responsible for Joubert syndrome, all of the proteins created from these genes affecting the cilia that are found on the cell surface. It can be confirmed through its hallmark molar tooth imprint that shows up on brain scans of the patient, a visualization of the malformed brain stem and cerebellar vermis.

Lactose intolerance is a condition in which the body does not support the ingestion of lactose through the consumption of milk, cheese, and other dairy products. This intolerance occurs due to the lack of the enzyme intestinal lactase, which is an enzyme found in newborns. The frequency of this enzyme declines rapidly after the child stops breastfeeding. Lactase deficiency is most prevalent in Asia, Africa and Indigenous populations in North and South America. The symptoms of lactose intolerance include diarrhea, bloating, abdominal pain and excessive flatus. The cause of these symptoms is the processing of the ingested lactose being fermented by intestinal bacteria instead of in the small intestine, where lactose is meant to be processed.

Homocystinuria, Cystathionine beta-Synthase Deficiency, also known as homocystinuria, is a inherited disorder of amino acid methionine metabolism caused by a defective cystathionine beta-Synthase. Cystathionine beta-Synthase catalyzes the conversion of homocysteine and L-Serine into L-Cystathionine which is the substrate of cystathionine gamma-lyase. This disorder is characterized by a large accumulation of homocysteine in the cell. Symptoms of the disorder include thromboembolism, ectopia lentis and/or severe myopia, skeletal system deficiency and developmental delay. Treatment with homocystinuria aims at correct the biochemical abnormalities through disorder management (e.g. surveillance, circumstances to avoid, prevention of primary manifestations, etc.