Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2PP2BP4_Moderate
The NM_001083962.2(TCF4):āc.304A>Cā(p.Ser102Arg) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,612,718 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (ā ).
TCF4 (HGNC:11634): (transcription factor 4) This gene encodes transcription factor 4, a basic helix-loop-helix transcription factor. The encoded protein recognizes an Ephrussi-box ('E-box') binding site ('CANNTG') - a motif first identified in immunoglobulin enhancers. This gene is broadly expressed, and may play an important role in nervous system development. Defects in this gene are a cause of Pitt-Hopkins syndrome. In addition, an intronic CTG repeat normally numbering 10-37 repeat units can expand to >50 repeat units and cause Fuchs endothelial corneal dystrophy. Multiple alternatively spliced transcript variants that encode different proteins have been described. [provided by RefSeq, Jul 2016]
Verdict is Uncertain_significance. Variant got 1 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TCF4. . Gene score misZ: 4.1035 (greater than the threshold 3.09). Trascript score misZ: 4.5676 (greater than threshold 3.09). The gene has 42 curated pathogenic missense variants (we use a threshold of 10). The gene has 70 curated benign missense variants. GenCC has associacion of the gene with intellectual disability, corneal dystrophy, Fuchs endothelial, 3, autosomal dominant non-syndromic intellectual disability, autism spectrum disorder, Fuchs' endothelial dystrophy, Pitt-Hopkins syndrome.
BP4
Computational evidence support a benign effect (MetaRNN=0.18924263).
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Jul 19, 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: 1002665). This variant has not been reported in the literature in individuals affected with TCF4-related conditions. This variant is present in population databases (rs780638244, gnomAD 0.0009%). This sequence change replaces serine, which is neutral and polar, with arginine, which is basic and polar, at codon 102 of the TCF4 protein (p.Ser102Arg). -