Methylbutyryl-CoA dehydrogenase deficiency 2- ...; Glicinuria methylbutyryl, ... deficiency 2- (2-Methylbutyryl-CoA dehydrogenase deficiency; 2-Methylbutyryl glycinuria) - Gen ACADSB.
Deficiency 2-methylbutyryl-CoA dehydrogenase (2-MBADD), also known as 2-MBCD deficiency, is a rare process in which the body is unable to properly process proteins. Normally, the body breaks down food proteins into amino acids. Subsequently, the amino acids can be processed to provide energy to the body. People with deficiency of 2-methyl - butyryl-CoA dehydrogenase can not process the amino acid isoleucine. Most cases of deficiency of 2-methylbutyryl-CoA dehydrogenase are detected soon after birth by newborn screening, identifying abnormal concentrations of certain compounds in the blood. In individuals with this condition, the 2-methylbutyryl carnitine is elevated in blood and two-methylbutyrylglycine is elevated in the urine (2-metilbutirilglicinuria).
Most people with deficiency of 2-methyl - butyryl-CoA dehydrogenase have no health problems related to this process. A small percentage of affected people develop signs and symptoms of the disease, which may begin soon after birth or later in childhood. Often, the initial symptoms include lack of appetite, lack of energy, vomiting and irritability. These symptoms may progress to severe health problems such as respiratory distress, convulsions and coma. Additional problems may include poor growth, impaired vision, learning problems, muscle weakness and delayed development of motor skills.
It is not clear why some people with deficiency of 2-methyl - butyryl-CoA dehydrogenase develop health problems and others do not. It has been suggested that in some cases, signs and symptoms can be triggered by infections, periods of fasting, or a larger amount of protein - rich foods in the diet.
This process is due to mutations in the gene ACADSB (acyl-CoA dehydrogenase, short / branched chain), located on the long arm of chromosome 10 (10q26.13). This gene encodes the synthesis of 2-methylbutyryl-CoA dehydrogenase, which plays an important role in protein processing. In cells throughout the body, 2-methylbutyryl-CoA dehydrogenase are within mitochondria, which convert the energy from food in a way that cells can metabolize. The 2-methylbutyryl-CoA dehydrogenase enzyme helps break the amino acid isoleucine. Specifically, this enzyme helps the third stage of the process, performing a chemical reaction that converts a 2-methylbutyryl-CoA molecule called to another molecule, the tiglicol-CoA. Additional metabolic reactions convert tiglicol-CoA molecules used for energy.
There are more than 10 ACADSB gene mutations in people with deficiency of 2-methyl - butyryl-CoA dehydrogenase. Many gene mutations ACADSB replace one of the amino acid-methylbutyryl-CoA dehydrogenase 2 by incorrect amino acid. Other mutations result in the synthesis of an abnormally small of this enzyme in which several amino acids are absent version. As a consequence of these mutations, 2-methylbutyryl-CoA dehydrogenase has little or no activity. With a deficiency of normal enzyme activity, the body is unable to properly break down isoleucine. It is believed that some characteristics of this disease, such as lack of energy and muscle weakness occur because isoleucine is not processed to provide energy. In addition, the deterioration of 2-methyl - butyryl-CoA dehydrogenase may allow the accumulation of toxic compounds, which can lead to serious health problems.
This disease is inherited in an autosomal recessive pattern, which means that both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.
Tests in IVAMI: in IVAMI perform detection of mutations associated with deficiency of 2-methylbutyryl-CoA dehydrogenase, by complete PCR amplification of the exons of the gene ACADSB, and subsequent sequencing.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).