8-144359622-G-A

Variant names:

• chr8-144359622-G-A
• rs782305211
• NM_001363118.2:c.131-1G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_024531.5(SLC52A2):​c.131-1G>A variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000248 in 1,611,350 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: SLC52A2 NM_024531.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.39
• Publications: 0 publications found

Genes affected

SLC52A2 (HGNC:30224): (solute carrier family 52 member 2) This gene encodes a membrane protein which belongs to the riboflavin transporter family. In humans, riboflavin must be obtained by intestinal absorption because it cannot be synthesized by the body. The water-soluble vitamin riboflavin is processed to the coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) which then act as intermediaries in many cellular metabolic reactions. Paralogous members of the riboflavin transporter gene family are located on chromosomes 17 and 20. Unlike other members of this family, this gene has higher expression in brain tissue than small intestine. Alternative splicing of this gene results in multiple transcript variants encoding the same protein. Mutations in this gene have been associated with Brown-Vialetto-Van Laere syndrome 2 - an autosomal recessive progressive neurologic disorder characterized by deafness, bulbar dysfunction, and axial and limb hypotonia. [provided by RefSeq, Jul 2012]

FBXL6 (HGNC:13603): (F-box and leucine rich repeat protein 6) This gene encodes a member of a family of proteins that are characterized by an F-box motif. The encoded protein also contains leucine-rich repeats. F-box-containing proteins comprise one of the subunits of the SCF (SKP1-cullin-F-box) complex, which functions in phosphorylation-dependent ubiquitination. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 7.3, offset of 1, new splice context is: cctcctcccttccctgcaAGttg. 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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024531.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SLC52A2	NM_001363118.2	MANE Select	c.131-1G>A		splice_acceptor intron	N/A	NP_001350047.1
	SLC52A2	NM_001253815.2		c.131-1G>A		splice_acceptor intron	N/A	NP_001240744.1
	SLC52A2	NM_001253816.2		c.131-1G>A		splice_acceptor intron	N/A	NP_001240745.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SLC52A2	ENST00000643944.2	MANE Select	c.131-1G>A		splice_acceptor intron	N/A	ENSP00000496184.2
	SLC52A2	ENST00000329994.7	TSL:1	c.131-1G>A		splice_acceptor intron	N/A	ENSP00000333638.2
	SLC52A2	ENST00000402965.5	TSL:2	c.131-1G>A		splice_acceptor intron	N/A	ENSP00000385961.1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152196 Hom.: 0 Cov.: 33

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: 0.000282

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000800 AC: 2 AN: 250010 AF XY: 0.00000740

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: 0.0000929

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459154 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 725422

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33438

American (AMR) AF: 0.00 AC: 0 AN: 44638

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26008

East Asian (EAS) AF: 0.00 AC: 0 AN: 39628

South Asian (SAS) AF: 0.00 AC: 0 AN: 86146

European-Finnish (FIN) AF: 0.0000188 AC: 1 AN: 53220

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5746

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110076

Other (OTH) AF: 0.00 AC: 0 AN: 60254

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152196 Hom.: 0 Cov.: 33 AF XY: 0.0000404 AC XY: 3 AN XY: 74346

African (AFR) AF: 0.00 AC: 0 AN: 41458

American (AMR) AF: 0.00 AC: 0 AN: 15268

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5188

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.000282 AC: 3 AN: 10620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Benign	-0.15
CADD	Pathogenic	33
DANN	Uncertain	0.99
Eigen	Pathogenic	0.81
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Uncertain	0.90	D
PhyloP100		6.4
GERP RS		3.5
PromoterAI		0.0039	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=5/95	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.85
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.26		Position offset: 2
DS_AL_spliceai		0.99		Position offset: 1

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

Other links and lift over

dbSNP: rs782305211; hg19: chr8-145583282;