Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate
The NM_018027.5(FRMD4A):c.3104A>G(p.Gln1035Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000019 in 1,582,076 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).
FRMD4A (HGNC:25491): (FERM domain containing 4A) This gene encodes a FERM domain-containing protein that regulates epithelial cell polarity. It connects ADP ribosylation factor 6 (ARF6) with the Par protein complex, which regulates the remodeling of adherens junctions and linear actin cable formation during epithelial cell polarization. Polymorphisms in this gene are associated with Alzheimer's disease, and also with nicotine dependence. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2015]
PRPF18 (HGNC:17351): (pre-mRNA processing factor 18) Pre-mRNA splicing occurs in 2 sequential transesterification steps. The protein encoded by this gene is found to be essential for the catalytic step II in pre-mRNA splicing process. It is found in the spliceosome, and contains seven WD repeats, which function in protein-protein interactions. This protein has a sequence similarity to the yeast splicing factor Prp18. [provided by RefSeq, Jul 2008]
⚠️ 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:
32946
American (AMR)
AF:
0.00
AC:
0
AN:
44696
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25968
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39522
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85596
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5712
European-Non Finnish (NFE)
AF:
0.00000185
AC:
2
AN:
1082762
Other (OTH)
AF:
0.00
AC:
0
AN:
59284
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.002339), which strongly suggests a high chance of mosaicism in these individuals.
The c.3104A>G (p.Q1035R) alteration is located in exon 24 (coding exon 23) of the FRMD4A gene. This alteration results from a A to G substitution at nucleotide position 3104, causing the glutamine (Q) at amino acid position 1035 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -