NM_172250.3:c.-5C>T

Variant names:

• chr4-145639135-C-T
• rs750568846
• NM_172250.3:c.-5C>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_172250.3(MMAA):​c.-5C>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,461,784 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000011 (0 hom.)
• Consequence: MMAA NM_172250.3 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.74
• Publications: 0 publications found

Genes affected

MMAA (HGNC:18871): (metabolism of cobalamin associated A) The protein encoded by this gene is involved in the translocation of cobalamin into the mitochondrion, where it is used in the final steps of adenosylcobalamin synthesis. Adenosylcobalamin is a coenzyme required for the activity of methylmalonyl-CoA mutase. Defects in this gene are a cause of methylmalonic aciduria. [provided by RefSeq, Jul 2008]

MMAA Gene-Disease associations (from GenCC):

• methylmalonic aciduria, cblA type

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Myriad Women’s Health, Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet, G2P

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.52).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MMAA	NM_172250.3	c.-5C>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 2 of 7	ENST00000649156.2	NP_758454.1
MMAA	NM_172250.3	c.-5C>T		5_prime_UTR_variant	Exon 2 of 7	ENST00000649156.2	NP_758454.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMAA	ENST00000649156.2	c.-5C>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 2 of 7		NM_172250.3	ENSP00000497008.1
MMAA	ENST00000649156.2	c.-5C>T		5_prime_UTR_variant	Exon 2 of 7		NM_172250.3	ENSP00000497008.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251350 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000109 AC: 16 AN: 1461784 Hom.: 0 Cov.: 31 AF XY: 0.0000151 AC XY: 11 AN XY: 727188

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53394

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000126 AC: 14 AN: 1111950

Other (OTH) AF: 0.0000166 AC: 1 AN: 60390

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000225 Hom.: 1

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.52
CADD	Benign	15
DANN	Benign	0.80
PhyloP100		2.7

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

Other links and lift over

dbSNP: rs750568846; hg19: chr4-146560287; COSMIC: COSV99849556; COSMIC: COSV99849556;