16-67657610-A-T

Variant summary

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

The NM_001082486.2(ACD):c.1373T>A(p.Met458Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,830 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/19 in silico tools predict 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. M458T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ACD NM_001082486.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.422

Genes affected

ACD (HGNC:25070): (ACD shelterin complex subunit and telomerase recruitment factor) This gene encodes a protein that is involved in telomere function. This protein is one of six core proteins in the telosome/shelterin telomeric complex, which functions to maintain telomere length and to protect telomere ends. Through its interaction with other components, this protein plays a key role in the assembly and stabilization of this complex, and it mediates the access of telomerase to the telomere. Multiple transcript variants encoding different isoforms have been found for this gene. This gene, which is also referred to as TPP1, is distinct from the unrelated TPP1 gene on chromosome 11, which encodes tripeptidyl-peptidase I. [provided by RefSeq, Jul 2008]

CARMIL2 (HGNC:27089): (capping protein regulator and myosin 1 linker 2) This gene encodes a member of the CARMIL (capping protein, Arp2/3, myosin-I linker) family of proteins. The encoded protein interacts with and negatively regulates the heterodimeric capping protein and promotes cell migration. Reduced expression of this gene has been observed in human psoriasis patients. Mutations in this gene cause a human immunodeficiency syndrome characterized by smooth muscle tumors and impaired T-cell function. [provided by RefSeq, May 2017]

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=0.13725656).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACD	NM_001082486.2	c.1373T>A	p.Met458Lys	missense_variant	12/12	ENST00000620761.6
CARMIL2	NM_001013838.3			downstream_gene_variant		ENST00000334583.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACD	ENST00000620761.6	c.1373T>A	p.Met458Lys	missense_variant	12/12	1	NM_001082486.2	P1
CARMIL2	ENST00000334583.11			downstream_gene_variant		1	NM_001013838.3	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461830 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 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: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000282 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dyskeratosis congenita, autosomal dominant 6 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 19, 2022

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. This sequence change replaces methionine, which is neutral and non-polar, with lysine, which is basic and polar, at codon 544 of the ACD protein (p.Met544Lys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ACD-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.23
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.55
Cadd	Benign	8.6
Dann	Benign	0.94
Eigen	Benign	-0.78
Eigen_PC	Benign	-0.77
FATHMM_MKL	Benign	0.23	N
LIST_S2	Benign	0.46	T;T;.;T;T;.
M_CAP	Benign	0.023	T
MetaRNN	Benign	0.14	T;T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	0.99	N;N
PrimateAI	Benign	0.41	T
REVEL	Benign	0.029
Polyphen		0.14, 0.21	.;B;.;.;.;B
Vest4		0.30, 0.28, 0.27
MutPred		0.27		.;Gain of ubiquitination at M544 (P = 0.0177);.;.;.;.;
MVP		0.30
MPC		0.21
ClinPred		0.16	T
GERP RS		2.8
Varity_R		0.33
gMVP		0.20

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: rs1320429671; hg19: chr16-67691513;