Global Evidence of Screening for Homocystinuria
Homocystinuria is a rare inherited disorder occurs due to cystathionine beta synthase enzyme deficiency.An autosomal recessive disorder.This disease belong to group of hereditary metabolic disorders. This disease cause an accumulation of the amino acid homocysteine in the serum and an increased excretion of homocysteine in the urine. This disease can acquired with B6, B12, and Folate deficiency.
Clinical features and complications include ectopia lentis ,myopia, glaucoma, mental retardation ,developmental delay, pectus excavatum , marfanoid habitus,osteoporosis . Individuals with this condition appear normal at birth. But they can develop serious complications in childhood. Early diagnosis and treatment can prevent or reduce the severity of the complications such as Thromboembolic disorders.1
Newborn screening for Homocystinuria first started in late 1960 s. First used bacterial inhibition assay( For measuring methionine concentration in dried blood spots) for the screening. Then thin layer amino acid chromatography was used . Analysis of methionine levels by tandem mass spectrometry is the recent test use for newborn screening in homocystinuria.2
7 infants with classic homocystinuria were identified of 12,603 native Qatari infants over 2 years.
Over a period of 3 years, a total of 14 cases of classic homocystinuria were detected by screening of homocysteine from all newborn infants born in Qatar (n = 46 406).3
Highest incidence of Homocystinuria in the world is 1:1,800. Reported in Qatari population.4
In multiple screening programme on Italy; Out of 116,000 newborn infants screened for aminoacidopathies 2 cases of homocystinuria were detected.