NM_017838.4:c.455C>T

Variant names:

• chr5-178149720-G-A
• rs1417164552
• NM_017838.4:c.455C>T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_017838.4(NHP2):​c.455C>T​(p.Pro152Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,542 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: NHP2 NM_017838.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.90

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.833

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NHP2	NM_017838.4	c.455C>T	p.Pro152Leu	missense_variant	Exon 4 of 4	ENST00000274606.8	NP_060308.1
RMND5B	NM_022762.5	c.*1688G>A		3_prime_UTR_variant	Exon 11 of 11	ENST00000313386.9	NP_073599.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NHP2	ENST00000274606.8	c.455C>T	p.Pro152Leu	missense_variant	Exon 4 of 4	1	NM_017838.4	ENSP00000274606.4
RMND5B	ENST00000313386.9	c.*1688G>A		3_prime_UTR_variant	Exon 11 of 11	1	NM_022762.5	ENSP00000320623.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461542 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727090

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dyskeratosis congenita Uncertain:1

Oct 03, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with NHP2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 152 of the NHP2 protein (p.Pro152Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.70
BayesDel_addAF	Uncertain	0.16	D
BayesDel_noAF	Uncertain	-0.010
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.48	T
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.55	T
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.83	D
MetaSVM	Uncertain	0.27	D
MutationAssessor	Pathogenic	3.2	M
PrimateAI	Uncertain	0.51	T
PROVEAN	Pathogenic	-6.1	D
REVEL	Uncertain	0.50
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0030	D
Polyphen		1.0	D
Vest4		0.64
MutPred		0.41		Loss of glycosylation at P152 (P = 0.0346);
MVP		0.87
MPC		1.1
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.30
gMVP		0.65

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: rs1417164552; hg19: chr5-177576721;