5-178149736-G-T

Position:

• chr5-178149736-G-T

Variant summary

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

The NM_017838.4(NHP2):​c.439C>A​(p.Gln147Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000226 in 1,461,714 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q147H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000023 (0 hom.)
• Consequence: NHP2 NM_017838.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.94

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.07352877).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NHP2	NM_017838.4	c.439C>A	p.Gln147Lys	missense_variant	4/4	ENST00000274606.8
RMND5B	NM_022762.5	c.*1704G>T		3_prime_UTR_variant	11/11	ENST00000313386.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NHP2	ENST00000274606.8	c.439C>A	p.Gln147Lys	missense_variant	4/4	1	NM_017838.4	P1
RMND5B	ENST00000313386.9	c.*1704G>T		3_prime_UTR_variant	11/11	1	NM_022762.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000797 AC: 2 AN: 251068 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135788

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: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000226 AC: 33 AN: 1461714 Hom.: 0 Cov.: 31 AF XY: 0.0000206 AC XY: 15 AN XY: 727160

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: 0.0000297

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

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

Labcorp Genetics (formerly Invitae), Labcorp

Oct 13, 2023

This sequence change replaces glutamine, which is neutral and polar, with lysine, which is basic and polar, at codon 147 of the NHP2 protein (p.Gln147Lys). This variant is present in population databases (rs779452625, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with NHP2-related conditions. ClinVar contains an entry for this variant (Variation ID: 1374273). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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
AlphaMissense	Benign	0.092
BayesDel_addAF	Benign	-0.31	T
BayesDel_noAF	Benign	-0.67
CADD	Benign	17
DANN	Benign	0.76
DEOGEN2	Benign	0.084	T
Eigen	Benign	-0.41
Eigen_PC	Benign	-0.27
FATHMM_MKL	Benign	0.32	N
LIST_S2	Benign	0.71	T
M_CAP	Benign	0.0090	T
MetaRNN	Benign	0.074	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	-0.020	N
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.33	T
PROVEAN	Benign	0.29	N
REVEL	Benign	0.051
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Polyphen		0.030	B
Vest4		0.085
MutPred		0.38		Gain of methylation at Q147 (P = 0.013);
MVP		0.55
MPC		0.51
ClinPred		0.052	T
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.12
gMVP		0.36

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: rs779452625; hg19: chr5-177576737;