5-178149772-ACTC-A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PM4_Supporting

The NM_017838.4(NHP2):c.400_402del(p.Glu134del) variant causes a inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,746 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NHP2 NM_017838.4 inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.94

Genes affected

NHP2 (HGNC:14377): (NHP2 ribonucleoprotein) This gene is a member of the H/ACA snoRNPs (small nucleolar ribonucleoproteins) gene family. snoRNPs are involved in various aspects of rRNA processing and modification and have been classified into two families: C/D and H/ACA. The H/ACA snoRNPs also include the DKC1, NOLA1 and NOLA3 proteins. These four H/ACA snoRNP proteins localize to the dense fibrillar components of nucleoli and to coiled (Cajal) bodies in the nucleus. Both 18S rRNA production and rRNA pseudouridylation are impaired if any one of the four proteins is depleted. The four H/ACA snoRNP proteins are also components of the telomerase complex. This gene encodes a protein related to Saccharomyces cerevisiae Nhp2p. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2008]

RMND5B (HGNC:26181): (required for meiotic nuclear division 5 homolog B) Predicted to enable metal ion binding activity and ubiquitin protein ligase activity. Predicted to contribute to ubiquitin-protein transferase activity. Predicted to be involved in proteasome-mediated ubiquitin-dependent protein catabolic process. Located in cytosol. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_017838.4
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_017838.4. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NHP2	NM_017838.4	c.400_402del	p.Glu134del	inframe_deletion	4/4	ENST00000274606.8
RMND5B	NM_022762.5	c.*1744_*1746del		3_prime_UTR_variant	11/11	ENST00000313386.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NHP2	ENST00000274606.8	c.400_402del	p.Glu134del	inframe_deletion	4/4	1	NM_017838.4	P1
RMND5B	ENST00000313386.9	c.*1744_*1746del		3_prime_UTR_variant	11/11	1	NM_022762.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461746 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727184

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dyskeratosis congenita Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 02, 2019

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. Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the affected amino acid(s) is currently unknown. This variant has not been reported in the literature in individuals with NHP2-related conditions. This variant is not present in population databases (ExAC no frequency). This variant, c.400_402del, results in the deletion of 1 amino acid(s) of the NHP2 protein (p.Glu134del), but otherwise preserves the integrity of the reading frame. -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1756214889; hg19: chr5-177576773;