chr17-19661229-GCT-CC

Position:

• chr17-19661229-GCT-CC

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The ENST00000176643.11(ALDH3A2):​c.901_903delGCTinsCC​(p.Ala301fs) variant causes a frameshift, missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A301P) has been classified as Uncertain significance. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ALDH3A2 ENST00000176643.11 frameshift, missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 9.91

Genes affected

ALDH3A2 (HGNC:403): (aldehyde dehydrogenase 3 family member A2) Aldehyde dehydrogenase isozymes are thought to play a major role in the detoxification of aldehydes generated by alcohol metabolism and lipid peroxidation. This gene product catalyzes the oxidation of long-chain aliphatic aldehydes to fatty acid. Mutations in the gene cause Sjogren-Larsson syndrome. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ALDH3A2 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-19661229-GCT-CC is Pathogenic according to our data. Variant chr17-19661229-GCT-CC is described in ClinVar as [Likely_pathogenic]. Clinvar id is 189187.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALDH3A2	NM_000382.3	c.901_903delGCTinsCC	p.Ala301fs	frameshift_variant, missense_variant	6/10	ENST00000176643.11	NP_000373.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALDH3A2	ENST00000176643.11	c.901_903delGCTinsCC	p.Ala301fs	frameshift_variant, missense_variant	6/10	1	NM_000382.3	ENSP00000176643.6

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Sjögren-Larsson syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 26, 2021	Variant summary: ALDH3A2 c.901_903delinsCC (p.Ala301ProfsX13) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 282830 control chromosomes. c.901_903delinsCC has been reported in the literature with a legacy nomenclature of c.901G>C and c.906delT in individuals affected with Sjogren-Larsson Syndrome (example, Sillen_1998, Keller_2010). These data indicate that the variant is likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in 10%-<30% of normal fatty aldehyde dehydrogenase enzyme activity in patient fibroblasts (example, Keller_2010). One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Feb 19, 2015	- -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs786204759; hg19: chr17-19564542;