Browsing pathways

Defects in 17-beta hydroxysteroid dehydrogenase III (HSD17B3) are the cause of male pseudohermaphrodism with gynecomastia. These individuals have unambiguous female external genitalia at birth, but fail to menstruate at the time of expected puberty and instead virilize as evidenced by growth of the phallus. A defect in HSD17B3 causes accumulation of dehydroepiandrosterone (DHA), and dehydroepiandrosterone sulfate (DHAS) as well as androstenedione in plasma.

L-2-Hydroxyglutaric Aciduria (D-2-Hydroxyglutaric Aciduria ) is an autosomal recessive disease caused by a mutation in the L2HGDH gene which codes for L-2-Hydroxygluarate dehydrogenase. A deficiency in this enzyme results in accumulation of L-2-Hydroxyglutaric acid in plasma, spinal fluid, and urine; and L-lysine in plasma and spinal fluid. Symptoms, which present at birth, include ataxia, hypotonia, mental retardation, and seizures. Premature death often results. D-2-Hydroxyglutaric Aciduria is an autosomal recessive disease caused by a mutation in the D2HGDH gene which does for D-2-Hydroxygluarate dehydrogenase. A deficiency in this enzyme results in accumulation of D-2-Hydroxyglutaric acid in plasma, spinal fluid, and urine; oxoglutaric acid in urine; and gabba-aminobutyric acid in spinal fluid. Symptoms, which present at birth, include ataxia, hypotonia, mental retardation, and seizures. Premature death often results.

2-Methyl-3-hydroxybutyryl CoA dehydrogenase deficiency (Hydroxyl-CoA dehydrogenase deficiency; MHBD) is a rare inborn disease of metabolism caused by a mutation in the HSD17B10 gene which codes for 3-hydroxyacyl-CoA dehydrogenase type-2. A deficiency in this enzyme results in accumulation of L-lactic acid in blood, spinal fluid, and urine; 2-ethylhydracrylic acid, 2-methyl-3-hydroxybutyric acid, and tiglylglycine in urine. Symptoms include cerebal atrophy, motor and mental retardation, overactivity and behavior issues, seizures and progressive neurological defects leading to early death. Treatment includes a high carbohydrate and low protein diet.

3-Hydroxy-3-methylglutaryl-CoA lyase deficiency (3-Hydroxy-3-methylglutaric acidemia; Leucine metabolism, defect in, HMG-CoA lyase deficiency) is an autosomal recessive disease caused by a mutation in the HMGCL gene which codes for hydroxymethylglutaryl-CoA lyase. A deficiency in this enzyme results in accumulation of 3-hydroxymethylglutaric acid, 3-hydroxyisovaleric acid, 3-methylcrotonylglycine and 3-methylglutaconic acid (cis and trans form), and methylglutaric acid in urine; and ammonia in blood. Symptoms include cardiomyopathy, dehydration, hypotonia, lactic acidosis, and pancreatitis. Treatment includes a low-fat, low-protein, high-carbohydrate diet.

3-Methylcrotonyl-Coenzyme A Carboxylase Deficiency Type I(3-MCC Deficiency; MCCD Type I; Methylcrotonylglycinuria Type I; 3-Methylcrotonylglycinuria I) is caused by a defect in the MCCC1 and MCCC2 genes. 3-methylcrotonyl-coenzyme A carboxylase plays an essential role in breaking down proteins from the diet. Specifically, the enzyme is responsible for the fourth step in processing leucine. If a mutation in the MCCC1 or MCCC2 gene reduces or eliminates the activity of 3-methylcrotonyl-CoA carboxylase, the body is unable to process leucine properly. As a result, toxic byproducts of leucine processing build up to harmful levels, damaging the brain and nervous system. Symptoms include recurring episodes of vomiting and diarrhea, lethargy, hypotonia, seizures, and coma.

3-Methylglutaconic aciduria type 1 (3-Methylglutaconicaciduria; Aciduria, 3-methylglutaconic type I) is an autosomal recessive disease caused by a mutation in the AUH gene which codes for methylglutaconyl-CoA hydratase. A deficiency in this enzyme results in accumulation of 3-hydroxyisovaleric acid, 3-methylglutaconic acid, and methylglutaric acid in urine. Symptoms include hypoglycemia, low birth weight, coma, seizures, and mental retardation. Treatment includes a low protein diet.

3-Methylglutaconic aciduria type 3 (Costeff syndrome; Optic atrophy plus syndrome) is an autosomal recessive disease caused by a deficiency in the OPA3 code which does for optic atrophy 3 protein. A deficiency of this enzyme results in accumulation of 3-methylglutaconic acid and methylglutaric acid. Symptoms include ataxia, dysarthria, optic atrophy, and neurological deterioration.

3-Methylglutaconic Aciduria Type IV (MGA, Type IV; MGA4) is an autosomal recessive disease caused by a mutation in an unknown gene. This disease results in an accumulation of cis and trans 3-methylglutaconic acid. Symptoms include, anemia, hyperammonemia, mental retardation, optic atrophy, hypotonia and early death.

4-Hydroelectric acid/ succinic semialdehyde deydrogenase deficiency (SSADH; Gamma-hydroxybutyric acidemia) inhibits the formation of succinate from GABA. This deficiency results in urinary excretion of 4-hydroxybutyric acid. In vivo proton MR also indicates elevated GABA levels as compared with an age-matched control. Symptoms include ataxia, chorea or athetosis, motor retardation, seizures, macrocephaly and delayed or abnormal speech development.

5-Oxoprolinuria (5-Oxoprolinase deficiency) is a result of a defect in the gamma-glutamyl cycle due to either 5-oxoprolinase or glutathione synthetase deficiency. In the case of glutathione synthetase deficiency, the glycine is not incorporated into gamma-glutamylcysteine. In the case of 5-oxoprolinase, however, pyroglutamic acid accumulates. Symptoms include anemia, mental retardation, metabolic acidosis, respiratory distress and urolithiasis.