rs72552730

Positions:

• chr5-132387102-C-A
• chr5-132387102-C-G

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_003060.4(SLC22A5):​c.902C>A​(p.Ala301Asp) 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A301G) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SLC22A5 NM_003060.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.50

Genes affected

SLC22A5 (HGNC:10969): (solute carrier family 22 member 5) Polyspecific organic cation transporters in the liver, kidney, intestine, and other organs are critical for elimination of many endogenous small organic cations as well as a wide array of drugs and environmental toxins. The encoded protein is a plasma integral membrane protein which functions both as an organic cation transporter and as a sodium-dependent high affinity carnitine transporter. The encoded protein is involved in the active cellular uptake of carnitine. Mutations in this gene are the cause of systemic primary carnitine deficiency (CDSP), an autosomal recessive disorder manifested early in life by hypoketotic hypoglycemia and acute metabolic decompensation, and later in life by skeletal myopathy or cardiomyopathy. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Apr 2015]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr5-132387102-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1707649.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.989
• PP5: Variant 5-132387102-C-A is Pathogenic according to our data. Variant chr5-132387102-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 1459138.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr5-132387102-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SLC22A5	NM_003060.4	c.902C>A	p.Ala301Asp	missense_variant	5/10	ENST00000245407.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SLC22A5	ENST00000245407.8	c.902C>A	p.Ala301Asp	missense_variant	5/10	1	NM_003060.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Renal carnitine transport defect Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 02, 2021	Experimental studies have shown that this variant affects SLC22A5 protein function (PMID: 11058897). For these reasons, this variant has been classified as Pathogenic. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SLC22A5 protein function. This variant has been observed in individual(s) with primary carnitine deficiency (PMID: 11058897). ClinVar contains an entry for this variant (Variation ID: 25405). This variant is not present in population databases (ExAC no frequency). This sequence change replaces alanine with aspartic acid at codon 301 of the SLC22A5 protein (p.Ala301Asp). The alanine residue is highly conserved and there is a moderate physicochemical difference between alanine and aspartic acid. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 14, 2022	Variant summary: SLC22A5 c.902C>A (p.Ala301Asp) results in a non-conservative amino acid change located in the Major facilitator superfamily domain (IPR020846) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251496 control chromosomes (gnomAD). c.902C>A has been reported in the literature in at least one homozygous individual affected with Systemic Primary Carnitine Deficiency (e.g. Wang_2000, Frigeni_2017). Experimental evidence demonstrated the variant affects protein function, leading to residual carnitine transport activity that was <10% of wild-type. A ClinVar submitter (evaluation after 2014) cites the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.83	D;.;.
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Uncertain	0.29	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	0.82	D
MutationAssessor	Pathogenic	4.3	H;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.55	T
PROVEAN	Pathogenic	-6.0	D;D;D
REVEL	Pathogenic	0.74
Sift	Uncertain	0.0010	D;D;D
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		1.0	D;.;.
Vest4		0.97
MutPred		0.92		Gain of ubiquitination at K302 (P = 0.0931);.;.;
MVP		0.96
MPC		0.99
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.99
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs72552730; hg19: chr5-131722794;