Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2PM5PP3_StrongPP5
The NM_000190.4(HMBS):c.446G>A(p.Arg149Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R149L) has been classified as Likely pathogenic.
HMBS (HGNC:4982): (hydroxymethylbilane synthase) This gene encodes a member of the hydroxymethylbilane synthase superfamily. The encoded protein is the third enzyme of the heme biosynthetic pathway and catalyzes the head to tail condensation of four porphobilinogen molecules into the linear hydroxymethylbilane. Mutations in this gene are associated with the autosomal dominant disease acute intermittent porphyria. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008]
Verdict is Likely_pathogenic. Variant got 9 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.993
PP5
Variant 11-119090213-G-A is Pathogenic according to our data. Variant chr11-119090213-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 1449.Status of the report is no_assertion_criteria_provided, 0 stars.