Homocystinuria
Last updated 1 May 2023
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Homocystinuria is an inherited disorder in which the body is unable to process certain building blocks of proteins (amino acids) properly.
Description
Homocystinuria is an inherited disorder in which the body is unable to process certain building blocks of proteins (amino acids) properly.
The most common form of homocystinuria, called classic homocystinuria, is characterised by tall stature, nearsightedness (myopia), dislocation of the lens at the front of the eye, a higher risk of blood clotting disorders, and brittle bones that are prone to fracture (osteoporosis) or other skeletal abnormalities. Some affected individuals also have developmental delay and learning problems.
Less common forms of homocystinuria can cause intellectual disability, slower growth and weight gain (failure to thrive), seizures, and problems with movement. They can also cause and a blood disorder called megaloblastic anaemia, which occurs when a person has a low number of red blood cells (anaemia), and the remaining red blood cells are larger than normal (megaloblastic).
The signs and symptoms of homocystinuria typically develop during childhood, although some mildly affected people may not show signs and symptoms until adulthood.
Inheritance patterns
The source lists the following possible inheritance patterns: Autosomal recessive. More than one pattern can apply in different cases.
Related genes
Other names
Cystathionine beta synthase deficiency
Homocysteinemia
Related patient information and medicines
Patient information leaflet
Newborn bloodspot test
Babies w... When people with this condition go for a long period of time without eating there is a build-up of medium-chain fats inside the body, which can have a poisonous effect. Also, a sudden and severe drop in blood sugar levels can occur. All four devolved nations of the United Kingdom now offer screening for four other serious, but.
Patient information leaflet
Macrocytosis and macrocytic anaemia
The level of serum B12 in your blood. Tests of your liver function. Checks to rule out conditions which people with some types of macrocytic anaemia develop, such as diabetes, underactive thyroid gland, and homocystinuria (a condition in which a chemical called homocysteine and related substances build up in the blood and urine). If some rare.
Further reading and references
- Homocystinuria; MedlinePlus, National Library of Medicine.
- Adam S, Almeida MF, Carbasius Weber E, Champion H, Chan H, Daly A, Dixon M, Dokoupil K, Egli D, Evans S, Eyskens F, Faria A, Ferguson C, Hallam P, Heddrich-Ellerbrok M, Jacobs J, Jankowski C, Lachmann R, Lilje R, Link R, Lowry S, Luyten K, MacDonald A, Maritz C, Martins E, Meyer U, Muller E, Murphy E, Robertson LV, Rocha JC, Saruggia I, Schick P, Stafford J, Stoelen L, Terry A, Thom R, van den Hurk T, van Rijn M, van Teefelen-Heithoff A, Webster D, White FJ, Wildgoose J, Zweers H. Dietary practices in pyridoxine non-responsive homocystinuria: a European survey. Mol Genet Metab. 2013 Dec;110(4):454-9. doi: 10.1016/j.ymgme.2013.10.003. Epub 2013 Oct 10.
- Bublil EM, Majtan T. Classical homocystinuria: From cystathionine beta-synthase deficiency to novel enzyme therapies. Biochimie. 2020 Jun;173:48-56. doi: 10.1016/j.biochi.2019.12.007. Epub 2019 Dec 16.
- El-Said MF, Badii R, Bessisso MS, Shahbek N, El-Ali MG, El-Marikhie M, El-Zyoid M, Salem MS, Bener A, Hoffmann GF, Zschocke J. A common mutation in the CBS gene explains a high incidence of homocystinuria in the Qatari population. Hum Mutat. 2006 Jul;27(7):719. doi: 10.1002/humu.9436.
- Elsaid MF, Bener A, Lindner M, Alzyoud M, Shahbek N, Abdelrahman MO, Abdoh G, Bessisso MS, Zschocke J, Hoffmann GF. Are heterocygotes for classical homocystinuria at risk of vitamin B12 and folic acid deficiency? Mol Genet Metab. 2007 Sep-Oct;92(1-2):100-3. doi: 10.1016/j.ymgme.2007.06.010. Epub 2007 Aug 7.
- Kalantari S, Brezzi B, Bracciama V, Barreca A, Nozza P, Vaisitti T, Amoroso A, Deaglio S, Manganaro M, Porta F, Spada M. Adult-onset CblC deficiency: a challenging diagnosis involving different adult clinical specialists. Orphanet J Rare Dis. 2022 Feb 2;17(1):33. doi: 10.1186/s13023-022-02179-y.
- Majtan T, Kozich V, Kruger WD. Recent therapeutic approaches to cystathionine beta-synthase-deficient homocystinuria. Br J Pharmacol. 2023 Feb;180(3):264-278. doi: 10.1111/bph.15991. Epub 2022 Dec 8.
- Morrison T, Bosch F, Landolt MA, Kozich V, Huemer M, Morris AAM. Homocystinuria patient and caregiver survey: experiences of diagnosis and patient satisfaction. Orphanet J Rare Dis. 2021 Mar 10;16(1):124. doi: 10.1186/s13023-021-01764-x.
- Sacharow SJ, Levy HL. Homocystinuria due to Cystathionine Beta-Synthase Deficiency. 2004 Jan 15 [updated 2025 Sep 25]. In: Adam MP, Bick S, Mirzaa GM, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2026. Available from http://www.ncbi.nlm.nih.gov/books/NBK1524/
- Tran C, Bonafe L, Nuoffer JM, Rieger J, Berger MM. Adult classical homocystinuria requiring parenteral nutrition: Pitfalls and management. Clin Nutr. 2018 Aug;37(4):1114-1120. doi: 10.1016/j.clnu.2017.07.013. Epub 2017 Jul 25.
- Walter JH, Jahnke N, Remmington T. Newborn screening for homocystinuria. Cochrane Database Syst Rev. 2015 Oct 1;2015(10):CD008840. doi: 10.1002/14651858.CD008840.pub4.
- Watkins D, Rosenblatt DS. Inherited defects of cobalamin metabolism. Vitam Horm. 2022;119:355-376. doi: 10.1016/bs.vh.2022.01.010. Epub 2022 Feb 21.
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