10-30313752-G-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_018109.4(MTPAP):c.1606C>G(p.Pro536Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,866 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 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. P536R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: MTPAP NM_018109.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.74

Genes affected

MTPAP (HGNC:25532): (mitochondrial poly(A) polymerase) The protein encoded by this gene is a member of the DNA polymerase type-B-like family. This enzyme synthesizes the 3' poly(A) tail of mitochondrial transcripts and plays a role in replication-dependent histone mRNA degradation.[provided by RefSeq, Jan 2011]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.0438312).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MTPAP	NM_018109.4	c.1606C>G	p.Pro536Ala	missense_variant	9/9	ENST00000263063.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MTPAP	ENST00000263063.9	c.1606C>G	p.Pro536Ala	missense_variant	9/9	1	NM_018109.4	P1
MTPAP	ENST00000488290.5	n.3361C>G		non_coding_transcript_exon_variant	17/17	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461866 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727242

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

EpiCase AF: 0.000218

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 11, 2022

This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 536 of the MTPAP protein (p.Pro536Ala). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MTPAP-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The alanine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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	Benign	0.057
BayesDel_addAF	Benign	-0.38	T
BayesDel_noAF	Benign	-0.78
Cadd	Benign	0.0010
Dann	Benign	0.14
DEOGEN2	Benign	0.0074	T
Eigen	Benign	-1.7
Eigen_PC	Benign	-1.8
FATHMM_MKL	Benign	0.032	N
LIST_S2	Benign	0.21	T
M_CAP	Benign	0.0059	T
MetaRNN	Benign	0.044	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-0.81	N
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.21	T
PROVEAN	Benign	0.26	N
REVEL	Benign	0.024
Sift	Benign	1.0	T
Sift4G	Benign	0.92	T
Polyphen		0.0	B
Vest4		0.066
MutPred		0.22		Loss of glycosylation at P536 (P = 0.0175);
MVP		0.20
MPC		0.35
ClinPred		0.030	T
GERP RS		-9.0
Varity_R		0.0081
gMVP		0.088

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr10-30602681;