ABSTRACT
This study aimed to determine the mutation spectrum and prevalence of inborn errors of metabolism [IEM] among Emiratis. 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. 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. 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