rs867778700

Positions:

• chrX-14850659-G-A
• chrX-14850659-G-T

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_Strong BS2_Supporting

The NM_001018113.3(FANCB):​c.1342C>T​(p.Pro448Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000286 in 1,047,339 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 2 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. 14/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 22)
  • Exomes 𝑓: 0.0000029 (0 hom. 2 hem.)
• Consequence: FANCB NM_001018113.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.33

Genes affected

FANCB (HGNC:3583): (FA complementation group B) This gene encodes a member of the Fanconi anemia complementation group B. This protein is assembled into a nucleoprotein complex that is involved in the repair of DNA lesions. Mutations in this gene can cause chromosome instability and VACTERL syndrome with hydrocephalus. [provided by RefSeq, Apr 2016]

FANCB (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -5 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.06595549).
• BS2: High Hemizygotes in GnomAdExome4 at 2 XL geneVariant has number of hemizygotes lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FANCB	NM_001018113.3	c.1342C>T	p.Pro448Ser	missense_variant	7/10	ENST00000650831.1	NP_001018123.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FANCB	ENST00000650831.1	c.1342C>T	p.Pro448Ser	missense_variant	7/10		NM_001018113.3	ENSP00000498215.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome AF: 0.00000286 AC: 3 AN: 1047339 Hom.: 0 Cov.: 24 AF XY: 0.00000625 AC XY: 2 AN XY: 320169

Gnomad4 AFR exome AF: 0.0000394

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000387

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Fanconi anemia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 23, 2022

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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 246610). This variant has not been reported in the literature in individuals affected with FANCB-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 serine, which is neutral and polar, at codon 448 of the FANCB protein (p.Pro448Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.31	T
BayesDel_noAF	Benign	-0.69
CADD	Benign	2.5
DANN	Benign	0.12
DEOGEN2	Benign	0.076	T;T;T
FATHMM_MKL	Benign	0.40	N
LIST_S2	Benign	0.65	T;.;T
M_CAP	Benign	0.0026	T
MetaRNN	Benign	0.066	T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.90	L;L;.
PrimateAI	Benign	0.21	T
PROVEAN	Benign	-0.92	N;N;N
REVEL	Benign	0.049
Sift	Benign	0.97	T;T;T
Sift4G	Benign	1.0	T;T;T
Polyphen		0.21	B;B;.
Vest4		0.22
MutPred		0.42		Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);
MVP		0.15
MPC		0.11
ClinPred		0.073	T
GERP RS		2.0
Varity_R		0.033

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs867778700; hg19: chrX-14868781;