NM_003632.3:c.1163G>C
Variant summary
Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2PP3_ModeratePP5
The NM_003632.3(CNTNAP1):āc.1163G>Cā(p.Arg388Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,614,084 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_003632.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 5 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
CNTNAP1 | ENST00000264638.9 | c.1163G>C | p.Arg388Pro | missense_variant | Exon 8 of 24 | 1 | NM_003632.3 | ENSP00000264638.3 | ||
CNTNAP1 | ENST00000591662.1 | n.1163G>C | non_coding_transcript_exon_variant | Exon 8 of 24 | 1 | ENSP00000466571.1 | ||||
CNTNAP1 | ENST00000586801.1 | n.578G>C | non_coding_transcript_exon_variant | Exon 1 of 2 | 3 | |||||
ENSG00000267765 | ENST00000592440.1 | n.364-4296C>G | intron_variant | Intron 1 of 1 | 2 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152194Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251460Hom.: 0 AF XY: 0.00000736 AC XY: 1AN XY: 135918
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1461890Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 727248
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152194Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74342
ClinVar
Submissions by phenotype
Lethal congenital contracture syndrome 7 Pathogenic:1Uncertain:1
A recent study reported this c.1163G>C (p.R388P) variant in homozygous status in a patient with similar features including hypotonia, minimal gag reflex and abnormalities within cerebral white matter revealed by brain MRI (PMID: 27668699). -
The homozygous p.Arg388Pro variant in CNTNAP1 was identified by our study in 1 individual with congenital contracture syndrome. This individual, along with another homozygous individual, were reported in the literature (PMID: 27159321, 27668699, 29882456, 31395954). This variant has been identified in 0.003% (3/60004) of Latino/Admixed American chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs779027563). This variant has also been reported in ClinVar (Variation ID: 522842) and has been interpreted as likely pathogenic by Undiagnosed Diseases Network and Ambry Genetics, and pathogenic by OMIM. Of the 2 affected individuals, both were homozygotes, which increases the likelihood that the p.Arg388Pro variant is pathogenic (PMID: 27159321, 27668699, 29882456, 31395954). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. Computational prediction tools and conservation analyses do not provide strong support for or against an impact to the protein. The number of missense variants reported in CNTNAP1 in the general population is lower than expected, suggesting there is little benign variation in this gene and slightly increasing the possibility that a missense variant in this gene may not be tolerated. The phenotype of individuals homozygous for this variant is highly specific for lethal congenital contracture syndrome based on unique phenotype and strict clinical testing with disease (PMID: 29882456, PMID: 27668699) In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PM3, PP2, PP4, PM2_supporting (Richards 2015). -
Inborn genetic diseases Pathogenic:1
The c.1163G>C (p.R388P) alteration is located in exon 8 (coding exon 8) of the CNTNAP1 gene. This alteration results from a G to C substitution at nucleotide position 1163, causing the arginine (R) at amino acid position 388 to be replaced by a proline (P). Based on data from gnomAD, the C allele has an overall frequency of <0.001% (1/251460) total alleles studied. The highest observed frequency was 0.003% (1/30616) of South Asian alleles. This alteration was detected in the homozygous state in multiple individuals with CNTNAP1-related congenital hypomyelinating neuropathy (Mehta, 2016; Conant, 2018; Wojcik, 2019). This amino acid position is not well conserved in available vertebrate species. The in silico prediction for this alteration is inconclusive. Based on the available evidence, this alteration is classified as likely pathogenic. -
Neuropathy, congenital hypomyelinating, 3 Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at