Homocystinuria: clinical features

Genetics and biochemistry

• This is an in-born error of sulphur metabolism
• It is caused by a genetic deficiency of cystathionine beta-synthase (CBS)
• This enzyme converts homocysteine to cystathionine
• It may also be caused by methylene tetrahydrofolate reductase (MTHFR) deficiency
• The transmission is autosomal recessive

Metabolic phenotypes

Neurological features

Ophthalmic features

Skeletal abnormalities

Systemic vascular features

Psychiatric features

References

1. Morris AA, Kožich V, Santra S, et al. Guidelines for the diagnosis and management of cystathionine beta-synthase deficiency. J Inherit Metab Dis 2017; 40:49-74. 
2. Woods E, Dawson C, Senthil L, Geberhiwot T. Cerebral venous thrombosis as the first presentation of classical homocystinuria in an adult patient. BMJ Case Rep 2017; pii: bcr2016217477. 
3. Bishop L, Kanoff R, Charnas L, Krenzel C, Berry SA, Schimmenti LA. Severe methylenetetrahydrofolate reductase (MTHFR) deficiency: a case report of nonclassical homocystinuria. J Child Neurol 2008; 23:823-828.
4. Oliveira Santos M, Geraldes R, Conceição I. Peripheral nerve involvement in classic homocystinuria: an unusual association. BMJ Case Rep 2016; pii: bcr2016216255. 
5. Mulvihill A, Yap S, O'Keefe M, Howard PM, Naughten ER. Ocular findings among patients with late-diagnosed or poorly controlled homocystinuria compared with a screened, well-controlled population. J AAPOS 2001; 5:311-315.
6. And 5 more. Subscribe to see the full list

Related checklists

• Homocystinuria: differential diagnosis
• Homocystinuria: management
• Homocystinuria: surveillance
• Methylene tetrahydrofolate reductase (MTHFR) deficiency