4-53399809-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_030917.4(FIP1L1):c.785C>G(p.Ser262Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000304 in 1,613,228 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. S262P) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000032 (0 hom.)
• Consequence: FIP1L1 NM_030917.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.16

Genes affected

FIP1L1 (HGNC:19124): (factor interacting with PAPOLA and CPSF1) This gene encodes a subunit of the CPSF (cleavage and polyadenylation specificity factor) complex that polyadenylates the 3' end of mRNA precursors. This gene, the homolog of yeast Fip1 (factor interacting with PAP), binds to U-rich sequences of pre-mRNA and stimulates poly(A) polymerase activity. Its N-terminus contains a PAP-binding site and its C-terminus an RNA-binding domain. An interstitial chromosomal deletion on 4q12 creates an in-frame fusion of human genes FIP1L1 and PDGFRA (platelet-derived growth factor receptor, alpha). The FIP1L1-PDGFRA fusion gene encodes a constitutively activated tyrosine kinase that joins the first 233 amino acids of FIP1L1 to the last 523 amino acids of PDGFRA. This gene fusion and chromosomal deletion is the cause of some forms of idiopathic hypereosinophilic syndrome (HES). This syndrome, recently reclassified as chronic eosinophilic leukemia (CEL), is responsive to treatment with tyrosine kinase inhibitors. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3112941).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FIP1L1	NM_030917.4	c.785C>G	p.Ser262Cys	missense_variant	10/18	ENST00000337488.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FIP1L1	ENST00000337488.11	c.785C>G	p.Ser262Cys	missense_variant	10/18	1	NM_030917.4	P4

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151938 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251194 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135766

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: 0.0000322 AC: 47 AN: 1461290 Hom.: 0 Cov.: 30 AF XY: 0.0000344 AC XY: 25 AN XY: 726976

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: 0.0000405

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151938 Hom.: 0 Cov.: 32 AF XY: 0.0000270 AC XY: 2 AN XY: 74188

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.000478

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.00 AC: 0

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 18, 2022

The c.785C>G (p.S262C) alteration is located in exon 10 (coding exon 10) of the FIP1L1 gene. This alteration results from a C to G substitution at nucleotide position 785, causing the serine (S) at amino acid position 262 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.040	T
BayesDel_noAF	Benign	-0.28
Cadd	Pathogenic	29
Dann	Uncertain	0.99
DEOGEN2	Benign	0.10	T;.;.;.;.
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Uncertain	0.97	D;D;D;D;D
M_CAP	Benign	0.030	D
MetaRNN	Benign	0.31	T;T;T;T;T
MetaSVM	Benign	-0.61	T
MutationAssessor	Benign	1.5	L;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D
PROVEAN	Benign	-2.0	N;N;N;D;N
REVEL	Benign	0.15
Sift	Uncertain	0.0050	D;D;D;D;D
Sift4G	Uncertain	0.035	D;D;T;D;T
Polyphen		0.99	D;.;D;P;.
Vest4		0.55
MutPred		0.15		Gain of catalytic residue at L263 (P = 0.0213);.;.;.;Gain of catalytic residue at L263 (P = 0.0213);
MVP		0.41
MPC		1.4
ClinPred		0.72	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.18
gMVP		0.42

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: rs770135904; hg19: chr4-54265976;