[Analysis for phenylalanine hydroxylase gene mutations in 35 ethnic Hui children from Ningxia with phenylketonuria].

Objective: To determine the type and frequency of phenylalanine hydroxylase gene (PAH) mutations in ethnic Hui patients from Ningxia with phenylketonuria (PKU).

Methods: For 35 PKU children patients and 50 healthy individuals, all exons and promoters of the PAH gene were analyzed with PCR and direct sequencing.

Results: Twenty mutations, including 8 missense mutations (40%), 5 nonsense mutations (25%), 4 splice site mutations (20%) and 3 deletion mutants (15%) were discovered. The overall detection rate was 68.57% (48/70). Common mutations have included R243Q (12.86%), R241C (11.43%), EX6-96A to G (5.71%), Y356X (5.71%), R413P(4.29%) and Q232X(4.29%), whilst rarer ones have included S16fsX10 (2.86%), R111X (2.86%) and L430P (2.86%). Among these, S16fsX10, L430P, D222G and IVS11+ 1G to A have not been reported previously. Y414X and S303fsX38 have not been reported in Hui ethnic group. No mutation was detected in the 50 normal controls.

Conclusion: The types and distribution of PAH gene mutations in ethnic Hui from Ningxia have been different from other areas of China. The mutations also showed a rich diversity.