13-33016447-G-A

Variant names:

• chr13-33016447-G-A
• rs1173135737
• NM_004795.4:c.7G>A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_004795.4(KL):​c.7G>A​(p.Ala3Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000133 in 825,030 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A3S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.000013 (0 hom.)
• Consequence: KL NM_004795.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.634

Genes affected

KL (HGNC:6344): (klotho) This gene encodes a type-I membrane protein that is related to beta-glucosidases. Reduced production of this protein has been observed in patients with chronic renal failure (CRF), and this may be one of the factors underlying the degenerative processes (e.g., arteriosclerosis, osteoporosis, and skin atrophy) seen in CRF. Also, mutations within this protein have been associated with ageing and bone loss. [provided by RefSeq, Jul 2008]

LOC124903151 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.105270684).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KL	NM_004795.4	c.7G>A	p.Ala3Thr	missense_variant	Exon 1 of 5	ENST00000380099.4	NP_004786.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KL	ENST00000380099.4	c.7G>A	p.Ala3Thr	missense_variant	Exon 1 of 5	1	NM_004795.4	ENSP00000369442.3
KL	ENST00000487852.1	n.15G>A		non_coding_transcript_exon_variant	Exon 1 of 5	5

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 0.0000133 AC: 11 AN: 825030 Hom.: 0 Cov.: 26 AF XY: 0.0000105 AC XY: 4 AN XY: 382272

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000412

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000266

Gnomad4 OTH exome AF: 0.0000735

GnomAD4 genome Cov.: 30

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Mar 22, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.7G>A (p.A3T) alteration is located in exon 1 (coding exon 1) of the KL gene. This alteration results from a G to A substitution at nucleotide position 7, causing the alanine (A) at amino acid position 3 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1

Jul 01, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 3 of the KL protein (p.Ala3Thr). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with KL-related conditions. ClinVar contains an entry for this variant (Variation ID: 2568463). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.34
BayesDel_addAF	Benign	-0.31	T
BayesDel_noAF	Benign	-0.68
CADD	Benign	16
DANN	Uncertain	0.99
DEOGEN2	Benign	0.095	T
Eigen	Benign	-0.75
Eigen_PC	Benign	-0.75
FATHMM_MKL	Benign	0.062	N
LIST_S2	Benign	0.29	T
M_CAP	Uncertain	0.21	D
MetaRNN	Benign	0.11	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.0	N
PrimateAI	Pathogenic	0.84	D
PROVEAN	Benign	0.32	N
REVEL	Benign	0.025
Sift	Benign	0.10	T
Sift4G	Benign	0.098	T
Polyphen		0.35	B
Vest4		0.070
MutPred		0.23		Gain of catalytic residue at P2 (P = 5e-04);
MVP		0.35
MPC		0.97
ClinPred		0.20	T
GERP RS		2.1
Varity_R		0.036
gMVP		0.40

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: rs1173135737; hg19: chr13-33590585;