NM_000240.4:c.73+1G>C

Variant names:

• chrX-43656415-G-C
• rs1469759912
• NM_000240.4:c.73+1G>C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000240.4(MAOA):​c.73+1G>C variant causes a splice donor, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 22)
• Consequence: MAOA NM_000240.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.57

Genes affected

MAOA (HGNC:6833): (monoamine oxidase A) This gene is one of two neighboring gene family members that encode mitochondrial enzymes which catalyze the oxidative deamination of amines, such as dopamine, norepinephrine, and serotonin. Mutation of this gene results in Brunner syndrome. This gene has also been associated with a variety of other psychiatric disorders, including antisocial behavior. Alternatively spliced transcript variants encoding multiple isoforms have been observed. [provided by RefSeq, Jul 2012]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 4.1, offset of 41, new splice context is: ccaGTgagg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-43656415-G-C is Pathogenic according to our data. Variant chrX-43656415-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3659338.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MAOA	NM_000240.4	c.73+1G>C		splice_donor_variant, intron_variant	Intron 1 of 14	ENST00000338702.4	NP_000231.1
MAOA	NM_001270458.2	c.-435+1G>C		splice_donor_variant, intron_variant	Intron 1 of 15		NP_001257387.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MAOA	ENST00000338702.4	c.73+1G>C		splice_donor_variant, intron_variant	Intron 1 of 14	1	NM_000240.4	ENSP00000340684.3

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 22

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Brunner syndrome Pathogenic:1

Jul 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 1 of the MAOA gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in MAOA are known to be pathogenic (PMID: 8211186). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MAOA-related conditions. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	34
DANN	Uncertain	0.99
FATHMM_MKL	Uncertain	0.78	D
GERP RS		4.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.31		Position offset: 47
DS_DL_spliceai		1.0		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1469759912; hg19: chrX-43515663;