5-154889320-C-A

Variant names:

• chr5-154889320-C-A
• rs1763176914
• NM_015465.5:c.4359+1G>T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_015465.5(GEMIN5):​c.4359+1G>T variant causes a splice donor, intron change. 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: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: GEMIN5 NM_015465.5 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.49

Genes affected

GEMIN5 (HGNC:20043): (gem nuclear organelle associated protein 5) This gene encodes a WD repeat protein that is a component of the survival of motor neurons (SMN) complex. The SMN complex plays a critical role in mRNA splicing through the assembly of spliceosomal small nuclear ribonucleoproteins (snRNPs), and may also mediate the assembly and transport of other classes of ribonucleoproteins. The encoded protein is the snRNA-binding component of the SMN complex. Dysregulation of this gene may play a role in alternative mRNA splicing and tumor cell motility. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Nov 2011]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.021426994 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.1, offset of 24, new splice context is: ttgGTaaag. Cryptic site results in inframe 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 5-154889320-C-A is Pathogenic according to our data. Variant chr5-154889320-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 928549.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GEMIN5	NM_015465.5	c.4359+1G>T		splice_donor_variant, intron_variant	Intron 27 of 27	ENST00000285873.8	NP_056280.2
GEMIN5	NM_001252156.2	c.4356+1G>T		splice_donor_variant, intron_variant	Intron 27 of 27		NP_001239085.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GEMIN5	ENST00000285873.8	c.4359+1G>T		splice_donor_variant, intron_variant	Intron 27 of 27	1	NM_015465.5	ENSP00000285873.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1355016 Hom.: 0 Cov.: 20 AF XY: 0.00 AC XY: 0 AN XY: 679730

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000312 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

GEMIN5-related disorder Pathogenic:1

Jul 20, 2021

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GEMIN5 c.4359+1G>T is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: 4/4 predict the variant abolishes a 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 251188 control chromosomes (gnomAD). To our knowledge, no occurrence of c.4359+1G>T in individuals affected with GEMIN5-Related Disorders and no experimental evidence demonstrating its impact on protein function have been reported. However, a recent study (Kour_2021) reported 30 patients presenting with developmental delay, hypotonia, motor dysfunction, and cerebellar atrophy, harboring biallelic variants in the GEMIN5 gene, and four of the identified variants were predicted to result in loss-of-function (i.e. splice-site and frame-shift variants). In addition, Kour et al. demonstrated that pathogenic biallelic variants perturbed the subcellular distribution, and decreased the stability and expression of the GEMIN5 protein, resulting in impaired snRNP assembly; in addition, knock-down of the fly homolog of human GEMIN5, lead to motor dysfunction and developmental delay similar to human patients, suggesting a potential loss of function mechanism (Kour_2021). No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Uncertain	0.96	D
GERP RS		5.9

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.55		Position offset: -23
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: rs1763176914; hg19: chr5-154268880;