Prenatal diagnosis of citrullinemia type 1; seven families with c.1168G>A mutation of Argininosuccinate synthetase 1 gene in Southwest Iran: A case series

Background: Citrullinemia type 1 is an autosomal recessive disease resulting in ammonia accumulation in the blood, and if uncontrolled may progress to coma or death in the early months after birth. Cases presentation: 7 families from Southwest Iran having one or more children in their families or relatives, who died in the early months after birth due to citrullinemia type 1 visited for genetic counseling and prenatal diagnosis. Whole-exome sequencing was performed on peripheral blood specimens and chorionic villus samples. Sanger sequencing confirmed the genetic results. Both parents were identified as carriers for the exon 15 c.1168G>A mutation in each family. The fetus in 6 out of 7 families was homozygote for A substitution on the argininosuccinate synthetase 1 gene. Conclusion: The presence of a common mutation in the argininosuccinate synthetase 1 gene in all affected families of Southwest Iran shows a possible population cluster in this area. Key words: Argininosuccinate synthetase, Chorionic villus sampling, Point mutation.