Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM4PP3PP5_Moderate
The NM_001083962.2(TCF4):c.1817_1828delCCAAGCTCCTGA(p.Thr606_Leu609del) variant causes a disruptive inframe deletion change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type DEL_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Likely pathogenic (★).
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]
Our verdict: Likely_pathogenic. The variant received 7 ACMG points.
PM1
In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_001083962.2
PM4
Nonframeshift variant in NON repetitive region in NM_001083962.2.
PP3
No computational evidence supports a deleterious effect, but strongly conserved according to phyloP
PP5
Variant 18-55228897-ATCAGGAGCTTGG-A is Pathogenic according to our data. Variant chr18-55228897-ATCAGGAGCTTGG-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 431710.Status of the report is criteria_provided_single_submitter, 1 stars.