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Diseases

Genetic and Rare Diseases Information Center (GARD)

Methylcobalamin deficiency cbl G type


Other Names for this Disease
  • Homocystinuria-megaloblastic anemia, cblG complementation type
  • cblG
  • Methionine synthase deficiency
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Overview

Methylcobalamin deficiency cbl G type is a rare condition that occurs when the body is unable to process certain amino acids (building blocks of protein) properly. In most cases, signs and symptoms develop during the first year of life; however, the age of onset can range from infancy to adulthood. Common features of the condition include feeding difficulties, lethargy, seizures, poor muscle tone (hypotonia), developmental delay, microcephaly (unusually small head size), and megaloblastic anemia. Methylcobalamin deficiency cbl G type is caused by changes (mutations) in the MTR gene and is inherited in an autosomal recessive manner. Treatment generally includes regular doses of hydroxycobalamin (vitamin B12). Some affected people may also require supplementation with folates and betaine.[1][2]
Last updated: 12/3/2015

References

  1. Nuria Carrillo-Carrasco, MD, David Adams, MD, PhD, and Charles P Venditti, MD, PhD. Disorders of Intracellular Cobalamin Metabolism. GeneReviews. November 2013; http://www.ncbi.nlm.nih.gov/books/NBK1328/.
  2. Homocystinuria without methylmalonic aciduria. Orphanet. March 2012; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=622.
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Basic Information

  • Genetics Home Reference (GHR) contains information on Methylcobalamin deficiency cbl G type. This website is maintained by the National Library of Medicine.

In Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Methylcobalamin deficiency cbl G type. Click on the link to view a sample search on this topic.
Other Names for this Disease
  • Homocystinuria-megaloblastic anemia, cblG complementation type
  • cblG
  • Methionine synthase deficiency
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.