This variant was seen heterozygously (in combination with another variant in the same gene) in 3 out of 25 cases of hyperphenylalanimemia — phenylalanine concentrations in blood which are above the reference range but below what is considered diagnostic of phenylketonuria. The authors refer to 220 “normal chromosomes” from documented carriers as a control, with none of these carrying the variant. This could be summarized as case+: 3, case-: 22, cont+: 0, cont-: 220. This has a p-value of 0.00095.
This review classifies the variant as causing mild hyperphenylalaninemia