Kidney samples with this variant had significantly lower levels of HNMT activity & thermal stability, and COS-1 cells transiently expressing a construct with this variant had significantly lower HMNT activity.
Unable to access a copy of this paper online. OMIM reports that 192 cases and 237 were studies, with 54 alleles found in cases and 38 in controls. Counting alleles, this is case+: 54, case-: 330, control+: 38, control-: 436. This is p=0.005 and an OR of 1.88.
In a study of German children, in 261 children with asthma the allele frequency of this variant was 0.13 (similar to Yan et al), while in the 515 non-asthmatic controls the allele frequency was also 0.13. This contradicts Yan et al.‘s finding and is consistent with Sasaki et al’s negative report.