Holocarboxylase synthetase (HCS) deficiency was defined as a distinct genetic disorder several years after its initial clinical description, similar. Because of the acute and fulminant initial presentation of holocarboxylase synthetase (HCS) deficiency, treatment is almost always initiated in. Holocarboxylase synthetase deficiency is an inherited metabolic disorder in which the body is unable to use the vitamin biotin effectively. This disorder is.

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We need long-term secure funding to provide you the information that you need at your fingertips. Conditions to be considered in the differential diagnosis based on organic acids include biotinidase deficiency see this term and isolated carboxyalse deficiencies; based on hyperammonemia, include urea cycle defects see this term ; and based on neurological compromise and seizures in the neonatal period, include sepsis and other inborn errors of metabolism.

This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. Most patients present in the newborn or early infantile period, but some become symptomatic in the later infantile period summary by Suzuki et al. Mutations in the holocarboxylase synthetase gene HLCS. Morbidity in surviving affected individuals depends on the time of diagnosis and on the degree of damage related to metabolic crises.

Early detection and treatment often can prevent the severe outcomes of MCD. This means that a child must inherit two copies of the non-working gene for MCD, one from each parent, in order to have the condition. If your family is affected by holocarboxylase synthetase MCDwe would love to hear from youso that others may benefit from your story. In holocarboxylase synthetase deficiency MCDthe enzyme holocarboxylase synthetase is not working correctly.

Holocarboxylase synthetase deficiency

Holocarboxylase synthetase deficiency, a biotin-responsive multiple carboxylase holocarboxylaxe MCDis characterized by metabolic acidosis, lethargy, hypotonia, convulsions, and dermatitis. These other enzymes need biotin in order to break down food. A defect in biotinidase activity has been demonstrated in such patients Wolf et al. This article incorporates public domain text from The U.


Symptoms appeared at day 2 of life, with lactic acidosis, hyperammonemia, and urinary excretion of 3-hydroxyisovaleric acid, 3-methylcrotonylglycine, 3-hydroxypropionic acid, and methylcitric acid.

Conditions Holocarboxylase Synthetase Deficiency. Clinical onset is usually within holocarboxyalse, days or weeks of birth. Genetic counseling HCS deficiency is inherited as an autosomal recessive trait.

Without treatment, affected infants may progress to intractable seizures, cerebral edema and coma. The documents contained in this web site are presented for information purposes only.

A number sign is used with synthetasw entry because holocarboxylase synthetase deficiency is caused by homozygous or compound heterozygous mutation in the HLCS gene on chromosome 21q The neonatal-onset form presents as congenital lactic acidosis of variable severity with the underlying biochemical lesion in some families identified as an abnormal holocarboxylase synthetase with an elevated Km biotin and a decreased Synthetade. Other search option s Alphabetical list.

An out-of-range result may occur because the initial blood sample was too small or the test was performed too early.

The foregoing terms may include synonyms, similar disorders, variations in usage, and abbreviations. These medical problems may be life-threatening in some cases. Diagnostic methods Some affected individuals are identified through newborn screening by demonstration of abnormal organic acids, consistent with multiple carboxyalse deficiency.

Holocarboxylase synthetase deficiency – Wikipedia

Your input helps us improve the site for parents and practitioners. Biotin is a type of vitamin that your body needs to digest food. The primary treatment for HCS deficiency is free biotin supplementation which can improve the clinical status of symptomatic individuals with the enzyme deficiency and prevent some or all symptoms from developing in asymptomatic individuals with the disorder. Each family has a unique experience and each condition is very different.

The severe manifestations included lactic acidosis, alopecia, keratoconjunctivitis, perioral erosions, and seizures; all symptoms were completely reversed by biotin deficienct.

Inheritable biotin-treatable disorders and associated phenomena. Summary and related texts. Identification and characterization of mutations in patients with holocarboxylase synthetase deficiency.

Type 2 patients are characterized by normal fibroblast carboxylase activities at all biotin concentrations; a variable infantile-onset syndrome resembling biotin deficiency states; and a possible primary or secondary absorptive defect. However, you may find it useful to read the stories of families affected by other conditions, such as biotinidase deficiency, that may have similar evaluations and treatment.

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The HLCS gene makes an enzymeholocarboxylase synthetasethat attaches biotin to other molecules. Most of the reported patients with the early-onset form of the disorder were shown to have deficient holocarboxylase synthetase activity, with markedly elevated Michaelis constants of biotin for the enzyme Burri et al Mutations in the HLCS gene ho,ocarboxylase holocarboxylase synthetase deficiency.


Structure of human holocarboxylase synthetase gene and mutation spectrum of holocarboxylase synthetase deficiency. Children with these disorders usually develop neurologic symptoms and synthetawe compromise. Vitamins are also important to help our bodies break down food. The content you are trying to view is available only to logged in, current MedLink Neurology subscribers. Biotin, a B vitaminis found in foods such as liveregg yolksand milk.

When holocarboxylase synthetase is not working correctly, food cannot be broken down completely. The exact prevalence of HCSD is unknown, but the condition is one of the rarest inborn errors of metabolism. Was this page helpful? Inthe first patient diagnosed with such a disorder was reported as having biotin-responsive beta-methylcrotonylglycinuria Gompertz et al Failure to attach the biotin results in multiple carboxylase deficiency and accumulation of various, specific abnormal organic acids.

Six patients had later onset of symptoms 1 month to 3 yearswere treated with biotin, and showed normal development. Holocarboxylase synthetase deficiency is considered an organic acid condition because it can lead to a harmful buildup of organic acids and toxins in the body.

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