Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate
The NM_030917.4(FIP1L1):āc.1761C>Gā(p.Ser587Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,612,990 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (ā ).
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]
LNX1 (HGNC:6657): (ligand of numb-protein X 1) This gene encodes a membrane-bound protein that is involved in signal transduction and protein interactions. The encoded product is an E3 ubiquitin-protein ligase, which mediates ubiquitination and subsequent proteasomal degradation of proteins containing phosphotyrosine binding (PTB) domains. This protein may play an important role in tumorogenesis. Alternatively spliced transcript variants encoding distinct isoforms have been described. A pseudogene, which is located on chromosome 17, has been identified for this gene. [provided by RefSeq, Jul 2008]
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Jan 16, 2024
The c.1761C>G (p.S587R) alteration is located in exon 18 (coding exon 18) of the FIP1L1 gene. This alteration results from a C to G substitution at nucleotide position 1761, causing the serine (S) at amino acid position 587 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -