rs769348060

chr6-49459210-G-Achr6-49459210-G-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000255.4(MMUT):c.257C>T(p.Pro86Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,614,050 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P86R) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000021 (0 hom.)
• Consequence: MMUT NM_000255.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 9.52

Genes affected

MMUT (HGNC:7526): (methylmalonyl-CoA mutase) This gene encodes the mitochondrial enzyme methylmalonyl Coenzyme A mutase. In humans, the product of this gene is a vitamin B12-dependent enzyme which catalyzes the isomerization of methylmalonyl-CoA to succinyl-CoA, while in other species this enzyme may have different functions. Mutations in this gene may lead to various types of methylmalonic aciduria. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000255.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-49459210-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2780084.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988
• PP5: Variant 6-49459210-G-A is Pathogenic according to our data. Variant chr6-49459210-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 553773.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MMUT	NM_000255.4	c.257C>T	p.Pro86Leu	missense_variant	2/13	ENST00000274813.4
MMUT	XM_005249143.4	c.257C>T	p.Pro86Leu	missense_variant	2/13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MMUT	ENST00000274813.4	c.257C>T	p.Pro86Leu	missense_variant	2/13	1	NM_000255.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152160 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251474 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135912

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000980

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000205 AC: 30 AN: 1461890 Hom.: 0 Cov.: 31 AF XY: 0.0000193 AC XY: 14 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000198

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152160 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74340

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Mar 09, 2022	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Sep 06, 2017	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 20, 2023

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 86 of the MUT protein (p.Pro86Leu). This variant is present in population databases (rs769348060, gnomAD 0.01%). This missense change has been observed in individual(s) with methylmalonic acidemia due to methylmalonyl-CoA mutase deficiency (PMID: 16281286, 24330302, 27233228). ClinVar contains an entry for this variant (Variation ID: 553773). 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 MUT protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

MMUT-related disorder Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Mar 21, 2023

The MMUT c.257C>T variant is predicted to result in the amino acid substitution p.Pro86Leu. This variant has been reported in the compound heterozygous, presumed compound heterozygous, and homozygous states in individuals with methylmalonic acidemia (Worgan et al. 2006. PubMed ID: 16281286; Patient 31, Chu et al. 2016. PubMed ID: 27233228; Nr. 87, Hörster et al. 2020. PubMed ID: 32754920). The c.257C>T variant was also reported in the homozygous state in two unrelated individuals following newborn screening; however, both patients were asymptomatic (Underhill et al. 2013. PubMed ID: 24330302). This variant was also detected in a study of exome sequencing for inborn errors of metabolism in newborns (Supplemental Table 5, Adhikari et al. 2020. PubMed ID: 32778825). Based on in vitro analysis, the c.257C>T (p.Pro86Leu) variant was reported to result in a mild decrease in enzyme activity relative to control, and it was reported to be a thermolabile substitution (Forny et al. 2014. PubMed ID: 25125334). This variant is reported in 0.0098% of alleles in individuals of South Asian descent in gnomAD (http://gnomad.broadinstitute.org/variant/6-49426923-G-A) and is interpreted as pathogenic/likely pathogenic in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/553773/). This variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.62
Cadd	Pathogenic	29
Dann	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.47	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.93	D
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-9.2	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Vest4		0.98
MutPred		0.93		Loss of disorder (P = 0.0165);
MVP		1.0
MPC		0.49
ClinPred		1.0	D
GERP RS		5.6
gMVP		0.92

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: rs769348060; hg19: chr6-49426923;