mental retardation connective tissue disease inborn metabolic brain disease homocystinuria "Homocystinuria (disorder)" EXACT [SNOMEDCT_2005_07_31:11282001] "cystathionine synthase deficiency" EXACT [CSP2005:1849-0835] URI: http://www.ebi.ac.uk/cellline#homocystinuria MSH2010_2010_02_22:D006712 OMIM2009_05_01:MTHU008818 "Homocystinuria [Ambiguous]" EXACT [SNOMEDCT_2005_07_31:190709008] SNOMEDCT_2010_1_31:11282001 SNOMEDCT_2010_1_31:190709008 UMLS_CUI:C0019880 sulfuraminoacidemia