chr21-44573885-G-A

Variant names:

• chr21-44573885-G-A
• rs587770741
• NM_198687.2:c.127G>A

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_198687.2(KRTAP10-4):​c.127G>A​(p.Ala43Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 47)
  • Exomes 𝑓: 0.000027 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: KRTAP10-4 NM_198687.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.57
• Publications: 0 publications found

Genes affected

KRTAP10-4 (HGNC:20521): (keratin associated protein 10-4) This is an intronless gene located in a cluster of related genes on the q arm of chromosome 21. The proteins encoded by these genes form disulfide bonds with cysteine residues in hair keratins, thereby contributing to the structure and stability of hair fibers. [provided by RefSeq, Apr 2014]

TSPEAR (HGNC:1268): (thrombospondin type laminin G domain and EAR repeats) This gene encodes a protein that contains a N-terminal thrombospondin-type laminin G domain and several tandem arranged epilepsy-associated repeats (EARs). A mutation in this gene is the cause of autosomal recessive deafness-98. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Dec 2012]

TSPEAR Gene-Disease associations (from GenCC):

• ectodermal dysplasia 14, hair/tooth type with or without hypohidrosis

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive nonsyndromic hearing loss 98

  Inheritance: AR Classification: LIMITED, NO_KNOWN Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia
• nonsyndromic genetic hearing loss

  Inheritance: AR Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.034075677).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KRTAP10-4	NM_198687.2	c.127G>A	p.Ala43Thr	missense_variant	Exon 1 of 1	ENST00000400374.4	NP_941960.2
TSPEAR	NM_144991.3	c.83-5880C>T		intron_variant	Intron 1 of 11	ENST00000323084.9	NP_659428.2
TSPEAR	NM_001272037.2	c.-122-5880C>T		intron_variant	Intron 2 of 12		NP_001258966.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KRTAP10-4	ENST00000400374.4	c.127G>A	p.Ala43Thr	missense_variant	Exon 1 of 1	6	NM_198687.2	ENSP00000383225.3
TSPEAR	ENST00000323084.9	c.83-5880C>T		intron_variant	Intron 1 of 11	1	NM_144991.3	ENSP00000321987.4
TSPEAR	ENST00000642437.1	n.*28-5880C>T		intron_variant	Intron 2 of 12			ENSP00000496535.1
TSPEAR	ENST00000397916.1	n.-69C>T		upstream_gene_variant		1

Frequencies

GnomAD3 genomes AF: 0.0000200 AC: 3 AN: 149872 Hom.: 0 Cov.: 47

Gnomad AFR AF: 0.0000255

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000328 AC: 8 AN: 244134 AF XY: 0.0000301

Gnomad AFR exome AF: 0.000218

Gnomad AMR exome AF: 0.0000293

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000180

Gnomad OTH exome AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.0000267 AC: 39 AN: 1459196 Hom.: 0 Cov.: 232 AF XY: 0.0000331 AC XY: 24 AN XY: 725990

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.000190 AC: 6 AN: 31660

American (AMR) AF: 0.0000224 AC: 1 AN: 44640

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.0000253 AC: 1 AN: 39528

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86220

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5510

European-Non Finnish (NFE) AF: 0.0000252 AC: 28 AN: 1111924

Other (OTH) AF: 0.0000166 AC: 1 AN: 60210

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Data not reliable, filtered out with message: AS_VQSR AF: 0.0000200 AC: 3 AN: 149968 Hom.: 0 Cov.: 47 AF XY: 0.0000136 AC XY: 1 AN XY: 73384

African (AFR) AF: 0.0000254 AC: 1 AN: 39294

American (AMR) AF: 0.00 AC: 0 AN: 15234

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5186

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10632

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 292

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.000111 AC: 13

EpiCase AF: 0.00

EpiControl AF: 0.0000594

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Dec 03, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.127G>A (p.A43T) alteration is located in exon 1 (coding exon 1) of the KRTAP10-4 gene. This alteration results from a G to A substitution at nucleotide position 127, causing the alanine (A) at amino acid position 43 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.064
BayesDel_addAF	Benign	-0.26	T
BayesDel_noAF	Benign	-0.61
CADD	Benign	12
DANN	Benign	0.97
Eigen	Benign	-0.78
Eigen_PC	Benign	-0.83
FATHMM_MKL	Benign	0.073	N
LIST_S2	Benign	0.047	T;.;T
M_CAP	Benign	0.0033	T
MetaRNN	Benign	0.034	T;T;T
MetaSVM	Benign	-1.0	T
PhyloP100		-1.6
PrimateAI	Benign	0.22	T
PROVEAN	Benign	-1.2	.;N;.
REVEL	Benign	0.048
Sift	Benign	0.15	.;T;.
Sift4G	Benign	0.18	.;T;.
Vest4		0.076
MutPred		0.42		.;Gain of glycosylation at A43 (P = 0.0329);.;
MVP		0.067
MPC		0.60
ClinPred		0.027	T
GERP RS		1.6
PromoterAI		-0.029	Neutral
gMVP		0.041
Mutation Taster		=98/2	polymorphism

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

Other links and lift over

dbSNP: rs587770741; hg19: chr21-45993762; COSMIC: COSV59973527; COSMIC: COSV59973527;