NM_007254.4:c.308C>T
Variant summary
Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong
The NM_007254.4(PNKP):c.308C>T(p.Thr103Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000564 in 1,614,174 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_007254.4 missense
Scores
Clinical Significance
Conservation
Publications
- ataxia - oculomotor apraxia type 4Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P, Laboratory for Molecular Medicine
- microcephaly, seizures, and developmental delayInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- Charcot-Marie-Tooth disease type 2B2Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
- genetic developmental and epileptic encephalopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_benign. The variant received -4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000342 AC: 52AN: 152198Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000836 AC: 21AN: 251328 AF XY: 0.0000589 show subpopulations
GnomAD4 exome AF: 0.0000274 AC: 40AN: 1461858Hom.: 0 Cov.: 34 AF XY: 0.0000261 AC XY: 19AN XY: 727232 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000335 AC: 51AN: 152316Hom.: 0 Cov.: 32 AF XY: 0.000349 AC XY: 26AN XY: 74482 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:3
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In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 22508754) -
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not specified Uncertain:1
Variant summary: PNKP c.308C>T (p.Thr103Ile) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8.4e-05 in 251328 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in PNKP causing PNKP-Related Disorders, allowing no conclusion about variant significance. To our knowledge, no occurrence of c.308C>T in individuals affected with PNKP-Related Disorders and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 95482). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Inborn genetic diseases Uncertain:1
The p.T103I variant (also known as c.308C>T), located in coding exon 3 of the PNKP gene, results from a C to T substitution at nucleotide position 308. The threonine at codon 103 is replaced by isoleucine, an amino acid with similar properties. This amino acid position is well conserved on limited sequence alignment; however, isoleucine is the reference amino acid in other vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Developmental and epileptic encephalopathy, 12 Uncertain:1
This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 103 of the PNKP protein (p.Thr103Ile). This variant is present in population databases (rs115419706, gnomAD 0.1%). This variant has not been reported in the literature in individuals affected with PNKP-related conditions. ClinVar contains an entry for this variant (Variation ID: 95482). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The isoleucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at