X-130129965-C-A

Variant summary

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

The NM_004208.4(AIFM1):c.1770+5G>T variant causes a splice donor 5th base, 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 benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: AIFM1 NM_004208.4 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 0.9372
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.13

Genes affected

AIFM1 (HGNC:8768): (apoptosis inducing factor mitochondria associated 1) This gene encodes a flavoprotein essential for nuclear disassembly in apoptotic cells, and it is found in the mitochondrial intermembrane space in healthy cells. Induction of apoptosis results in the translocation of this protein to the nucleus where it affects chromosome condensation and fragmentation. In addition, this gene product induces mitochondria to release the apoptogenic proteins cytochrome c and caspase-9. Mutations in this gene cause combined oxidative phosphorylation deficiency 6 (COXPD6), a severe mitochondrial encephalomyopathy, as well as Cowchock syndrome, also known as X-linked recessive Charcot-Marie-Tooth disease-4 (CMTX-4), a disorder resulting in neuropathy, and axonal and motor-sensory defects with deafness and cognitive disability. Alternative splicing results in multiple transcript variants. A related pseudogene has been identified on chromosome 10. [provided by RefSeq, Aug 2015]

RAB33A (HGNC:):

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 (BayesDel_noAF=-0.32).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
AIFM1	NM_004208.4	c.1770+5G>T		splice_donor_5th_base_variant, intron_variant		ENST00000287295.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
AIFM1	ENST00000287295.8	c.1770+5G>T		splice_donor_5th_base_variant, intron_variant		1	NM_004208.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD3 exomes AF: 0.00000546 AC: 1 AN: 183067 Hom.: 0 AF XY: 0.0000148 AC XY: 1 AN XY: 67575

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000123

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Combined oxidative phosphorylation deficiency;CN118851:Charcot-Marie-Tooth Neuropathy X Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 24, 2021

This sequence change falls in intron 15 of the AIFM1 gene. It does not directly change the encoded amino acid sequence of the AIFM1 protein. It affects a nucleotide within the consensus splice site of the intron. This variant is present in population databases (rs754828679, ExAC 0.002%). This variant has not been reported in the literature in individuals affected with AIFM1-related conditions. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). 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 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
BayesDel_noAF	Benign	-0.32
Cadd	Benign	22
Dann	Benign	0.94

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.94
dbscSNV1_RF	Pathogenic	0.75
SpliceAI score (max)		0.13		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: rs754828679; hg19: chrX-129263940;