Question: What is (are) 3-Hydroxyisobutyric aciduria ?
Answer: 3-Hydroxyisobutyric aciduria is a rare metabolic condition in which the body is unable to breakdown certain amino acids (the building blocks of protein). This leads to a toxic buildup of particular acids known as organic acids in the blood (organic acidemia), tissues and urine (organic aciduria). Signs and symptoms of 3-hydroxyisobutyric aciduria include developmental delay, characteristic facial features and brain abnormalities. The exact underlying cause is not well understood; however, researchers believe some cases are caused by changes (mutations) in the ALDH6A1 gene and inherited in an autosomal recessive manner. Because it is so rare, there is limited evidence to support the effectiveness of treatment, but a protein-restricted diet and carnitine supplementation have been tried with varying degrees of success.
Source: GARD

Question: What are the symptoms of 3-Hydroxyisobutyric aciduria ?
Answer: What are the signs and symptoms of 3-Hydroxyisobutyric aciduria? The signs and symptoms of 3-hydroxyisobutyric aciduria vary but may include: Developmental delay Intellectual disability Failure to thrive Characteristic facial features including a long philtrum and small, low-set ears Unusually small head (microcephaly) Congenital brain abnormalities Nausea Diarrhea Dehydration Lethargy The severity of the condition can also vary significantly from person to person. Some affected people may only experience mild attacks of vomiting with normal development, while others experience failure to thrive with severe intellectual disability and early death. The Human Phenotype Ontology provides the following list of signs and symptoms for 3-Hydroxyisobutyric aciduria. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Aminoaciduria 90% Abnormality of the outer ear 50% Long philtrum 50% Triangular face 50% Aplasia/Hypoplasia of the cerebellum 7.5% Aplasia/Hypoplasia of the corpus callosum 7.5% Cerebral calcification 7.5% Cerebral cortical atrophy 7.5% Intrauterine growth retardation 7.5% Microcephaly 7.5% Seizures 7.5% Sloping forehead 7.5% Ventriculomegaly 7.5% Abnormal facial shape - Abnormality of neuronal migration - Autosomal recessive inheritance - Congenital intracerebral calcification - Episodic ketoacidosis - Failure to thrive - Lactic acidosis - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD

Question: What causes 3-Hydroxyisobutyric aciduria ?
Answer: What causes 3-hydroxyisobutyric aciduria? In many affected people, the exact underlying cause of 3-hydroxyisobutyric aciduria is poorly understood. Scientists believe that some cases are caused by changes (mutations) in the ALDH6A1 gene. This gene encodes an enzyme called methylmalonate semialdehyde dehydrogenase, which helps the body break down certain amino acids (the building blocks of protein) found in food. If this gene isn't working properly, the body is unable to break down the amino acids valine and thymine which leads to a build-up of toxic substances in the body and the many signs and symptoms of 3-hydroxyisobutyric aciduria.
Source: GARD

Question: Is 3-Hydroxyisobutyric aciduria inherited ?
Answer: Is 3-hydroxyisobutyric aciduria inherited? Cases of 3-hydroxyisobutyric aciduria thought to be caused by changes (mutations) in the ALDH6A1 gene are inherited in an autosomal recessive manner. This means that to be affected, a person must have a mutation in both copies of the responsible gene in each cell. The parents of an affected person usually each carry one mutated copy of the gene and are referred to as carriers. Carriers typically do not show signs or symptoms of the condition. When two carriers of an autosomal recessive condition have children, each child has a 25% (1 in 4) risk to have the condition, a 50% (1 in 2) risk to be a carrier like each of the parents, and a 25% chance to not have the condition and not be a carrier.
Source: GARD

Question: What are the treatments for 3-Hydroxyisobutyric aciduria ?
Answer: How might 3-hydroxyisobutyric aciduria be treated? There is no cure for 3-hydroxyisobutyric aciduria. Because it is so rare, there is limited evidence to support the effectiveness of treatment. However, affected people have been treated with a protein-restricted diet and carnitine supplementation with varying degrees of success.
Source: GARD