17-19664947-G-T

Variant names:

• chr17-19664947-G-T
• rs1036733598
• NM_000382.3:c.1108-1G>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000382.3(ALDH3A2):​c.1108-1G>T variant causes a splice acceptor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: ALDH3A2 NM_000382.3 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 8.99
• Publications: 1 publications found

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 Gene-Disease associations (from GenCC):

• Sjogren-Larsson syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Myriad Women’s Health, PanelApp Australia, Labcorp Genetics (formerly Invitae), Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-19664947-G-T is Pathogenic according to our data. Variant chr17-19664947-G-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 370471.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000382.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ALDH3A2	NM_000382.3	MANE Select	c.1108-1G>T		splice_acceptor intron	N/A	NP_000373.1
	ALDH3A2	NM_001031806.2		c.1108-1G>T		splice_acceptor intron	N/A	NP_001026976.1
	ALDH3A2	NM_001369136.1		c.1108-1G>T		splice_acceptor intron	N/A	NP_001356065.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ALDH3A2	ENST00000176643.11	TSL:1 MANE Select	c.1108-1G>T		splice_acceptor intron	N/A	ENSP00000176643.6
	ALDH3A2	ENST00000339618.8	TSL:1	c.1108-1G>T		splice_acceptor intron	N/A	ENSP00000345774.4
	ALDH3A2	ENST00000476965.5	TSL:1	n.858-1G>T		splice_acceptor intron	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Sjögren-Larsson syndrome Pathogenic:2

Feb 16, 2016

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.

Jan 10, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: ALDH3A2 c.1108-1G>T is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 251256 control chromosomes. To our knowledge, no occurrence of c.1108-1G>T in individuals affected with Sjogren-Larsson Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Another splice site variant at the same position has been classified by our lab as pathogenic (c.1108-1G>C). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic (n=1) and likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as likely pathogenic.

not provided Pathogenic:1

Feb 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects an acceptor splice site in intron 7 of the ALDH3A2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in ALDH3A2 are known to be pathogenic (PMID: 10577908, 10854114). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individuals with Sjögren-Larsson syndrome (PMID: 15241804, 16536828). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 370471). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	32
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.0
GERP RS		5.4
PromoterAI		0.0065	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AL_spliceai		1.0		Position offset: 1

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

Other links and lift over

dbSNP: rs1036733598; hg19: chr17-19568260;