NM_133433.4:c.7867C>T

Variant names:

• chr5-37063796-C-T
• rs1030959034
• NM_133433.4:c.7867C>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_133433.4(NIPBL):​c.7867C>T​(p.Leu2623Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,460,978 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. L2623I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NIPBL NM_133433.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.52
• Publications: 0 publications found

Genes affected

NIPBL (HGNC:28862): (NIPBL cohesin loading factor) This gene encodes the homolog of the Drosophila melanogaster Nipped-B gene product and fungal Scc2-type sister chromatid cohesion proteins. The Drosophila protein facilitates enhancer-promoter communication of remote enhancers and plays a role in developmental regulation. It is also homologous to a family of chromosomal adherins with broad roles in sister chromatid cohesion, chromosome condensation, and DNA repair. The human protein has a bipartite nuclear targeting sequence and a putative HEAT repeat. Condensins, cohesins and other complexes with chromosome-related functions also contain HEAT repeats. Mutations in this gene result in Cornelia de Lange syndrome, a disorder characterized by dysmorphic facial features, growth delay, limb reduction defects, and cognitive disability. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

NIPBL Gene-Disease associations (from GenCC):

• Cornelia de Lange syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• Cornelia de Lange syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.18887311).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NIPBL	NM_133433.4	c.7867C>T	p.Leu2623Phe	missense_variant	Exon 46 of 47	ENST00000282516.13	NP_597677.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NIPBL	ENST00000282516.13	c.7867C>T	p.Leu2623Phe	missense_variant	Exon 46 of 47	1	NM_133433.4	ENSP00000282516.8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1460978 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726676

⚠️ 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: 33474

American (AMR) AF: 0.0000224 AC: 1 AN: 44644

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39686

South Asian (SAS) AF: 0.00 AC: 0 AN: 86026

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53338

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111570

Other (OTH) AF: 0.00 AC: 0 AN: 60370

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cornelia de Lange syndrome 1 Uncertain:1

Feb 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 2623 of the NIPBL protein (p.Leu2623Phe). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with NIPBL-related conditions. ClinVar contains an entry for this variant (Variation ID: 2183671). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on NIPBL protein function. 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. -

not specified Uncertain:1

Oct 27, 2023

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: NIPBL c.7867C>T (p.Leu2623Phe) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 249206 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.7867C>T in individuals affected with Cornelia De Lange Syndrome 1 and no experimental evidence demonstrating its impact on protein function have been reported. One submitter has cited clinical-significance assessments for this variant to ClinVar after 2014 and has classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.25
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.070
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Benign	0.21	T;.
Eigen	Benign	0.14
Eigen_PC	Uncertain	0.29
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Uncertain	0.97	D;D
M_CAP	Benign	0.046	D
MetaRNN	Benign	0.19	T;T
MetaSVM	Uncertain	0.32	D
MutationAssessor	Benign	1.5	L;L
PhyloP100		3.5
PrimateAI	Pathogenic	0.84	D
PROVEAN	Benign	-1.2	N;N
REVEL	Uncertain	0.36
Sift	Benign	0.047	D;T
Sift4G	Benign	0.23	T;T
Polyphen		0.29	B;P
Vest4		0.38
MutPred		0.25		Gain of methylation at K2622 (P = 0.0334);Gain of methylation at K2622 (P = 0.0334);
MVP		0.78
MPC		1.2
ClinPred		0.68	D
GERP RS		5.5
Varity_R		0.15
gMVP		0.12
Mutation Taster		=72/28	polymorphism

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

Other links and lift over

dbSNP: rs1030959034; hg19: chr5-37063898;