18-63350953-C-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PP3_Strong PP5_Moderate

The NM_002035.4(KDSR):c.544G>A(p.Gly182Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,828 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: KDSR NM_002035.4 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.91

Genes affected

KDSR (HGNC:4021): (3-ketodihydrosphingosine reductase) The protein encoded by this gene catalyzes the reduction of 3-ketodihydrosphingosine to dihydrosphingosine. The putative active site residues of the encoded protein are found on the cytosolic side of the endoplasmic reticulum membrane. A chromosomal rearrangement involving this gene is a cause of follicular lymphoma, also known as type II chronic lymphatic leukemia. The mutation of a conserved residue in the bovine ortholog causes spinal muscular atrophy. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a topological_domain Cytoplasmic (size 244) in uniprot entity KDSR_HUMAN there are 4 pathogenic changes around while only 1 benign (80%) in NM_002035.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.939
• PP5: Variant 18-63350953-C-T is Pathogenic according to our data. Variant chr18-63350953-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2572585.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KDSR	NM_002035.4	c.544G>A	p.Gly182Ser	missense_variant	6/10	ENST00000645214.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KDSR	ENST00000645214.2	c.544G>A	p.Gly182Ser	missense_variant	6/10		NM_002035.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251324 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135832

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461828 Hom.: 0 Cov.: 31 AF XY: 0.00000825 AC XY: 6 AN XY: 727218

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Erythrokeratodermia variabilis et progressiva 4 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

3billion

-

The homozygous missense variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). Functional studies provide moderate evidence of having a damaging effect on the gene or gene product (PMID: 28774589). In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.84; 3Cnet: 0.21). The same nucleotide change resulting in the same amino acid change has been previously reported to be associated with KDSR-related disorder (PMID: 28774589). Therefore, this variant is classified as likely pathogenic according to the recommendation of ACMG/AMP guideline. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.72
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
Cadd	Pathogenic	27
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.82	D;D;.
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.66
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.94	D;D;D
MetaSVM	Pathogenic	0.83	D
MutationAssessor	Uncertain	2.6	M;M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.86	D
Polyphen		1.0	D;D;.
Vest4		0.97
MutPred		0.75		Gain of catalytic residue at G182 (P = 0.0654);Gain of catalytic residue at G182 (P = 0.0654);Gain of catalytic residue at G182 (P = 0.0654);
MVP		0.99
MPC		0.99
ClinPred		1.0	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.86
gMVP		0.91

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs751571336; hg19: chr18-61018186;