Mutation Spectrum and Birth Prevalence of Inborn Errors of Metabolism among EmiratisA study from Tawam Hospital Metabolic Center, United Arab Emirates

Objectives: this study aimed to determine the mutation spectrum and prevalence of inborn errors of metabolism (iem) among emiratis. methods: the reported mutation spectrum included all patients who were diagnosed with iem (excluding those with lysosomal storage diseases [lsd]) at tawam hospital metabolic center in abu dhabi, united arab emirates, between january 1995 and may 2013. disease prevalence (per 100,000 live births) was estimated from data available for 1995–2011. results: in 189 patients, 57 distinct iem were diagnosed, of which 20 (35%) entities were previously reported lsd (65 patients with 39 mutations), with a birth prevalence of 26.87/100,000. this study investigated the remaining 37 (65%) patients with other iem (124 patients with 62 mutations). mutation analysis was performed on 108 (87%) of the 124 patients. five patients with biotinidase deficiency had compound heterozygous mutations, and two siblings with lysinuric protein intolerance had two homozygous mutations. the remaining 103 (95%) patients had homozygous mutations. as of this study, 29 (47%) of the mutations have been reported only in emiratis. two mutations were found in three tribes (biotinidase deficiency [btd, c.1330g>c] and phenylketonuria [pah, c.168+5g>c]). two mutations were found in two tribes (isovaleric aciduria [ivd, c.1184g>a] and propionic aciduria [pccb, c.990dupt]). the remaining 58 (94%) mutations were each found in individual tribes. the prevalence was 48.37/100,000. the most prevalent diseases (2.2–4.9/100,000) were biotinidase deficiency; tyrosinemia type 1; phenylketonuria; propionic aciduria; glutaric aciduria type 1; glycogen storage disease type ia, and mitochondrial deoxyribonucleic acid depletion. conclusion: the iem birth prevalence (lsd and non-lsd) was 75.24/100,000. these results justify implementing prevention programmes that incorporate genetic counselling and screening.