1-197101467-TTC-T
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_018136.5(ASPM):c.7782_7783delGA(p.Lys2595SerfsTer6) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000176 in 1,609,224 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_018136.5 frameshift
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
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ASPM | NM_018136.5 | c.7782_7783delGA | p.Lys2595SerfsTer6 | frameshift_variant | Exon 18 of 28 | ENST00000367409.9 | NP_060606.3 | |
ASPM | NM_001206846.2 | c.4066-5305_4066-5304delGA | intron_variant | Intron 17 of 26 | NP_001193775.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000178 AC: 27AN: 151784Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.000235 AC: 58AN: 247162Hom.: 0 AF XY: 0.000172 AC XY: 23AN XY: 133812
GnomAD4 exome AF: 0.000176 AC: 256AN: 1457322Hom.: 0 AF XY: 0.000164 AC XY: 119AN XY: 725108
GnomAD4 genome AF: 0.000178 AC: 27AN: 151902Hom.: 0 Cov.: 32 AF XY: 0.000189 AC XY: 14AN XY: 74266
ClinVar
Submissions by phenotype
Microcephaly 5, primary, autosomal recessive Pathogenic:16Other:1
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ACMG classification criteria: PVS1 very strong, PS4 strong, PM3 strong -
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The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.022%). Predicted Consequence/Location: Frameshift: predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000021606 /PMID: 19028728). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -
This variant was previously reported in individuals affected with autosomal recessive primary microcephaly [PMID: 19028728, 23611254, 29644084, 31589614]. Loss-of-function variants in the ASPM gene are known to be pathogenic [PMID: 19028728, 23611254] -
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PVS1,PM3 (strong), PM2 -
A Homozygous two base pair deletion in exon 18 of the ASPM gene that results in a frameshift and premature truncation of the protein 6 amino acids downstream to codon 2595 was detected. The observed variant c.7782_7783del (p.Lys2595SerfsTer6) has not been reported in the 1000 genomes database and has a minor allele frequency of 0.03% in the ExAC database. The in silico prediction of the variant is damaging by MutationTaster2. The reference region is conserved across mammals. -
Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with microcephaly 5, primary (MIM#608716). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0201 - Variant is predicted to cause nonsense-mediated decay (NMD) and loss of protein (premature termination codon is located at least 54 nucleotides upstream of the final exon-exon junction). (SP) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD <0.01 for a recessive condition (v2: 62 heterozygotes, 0 homozygotes). (SP) 0701 - Other NMD-predicted variants comparable to the one identified in this case have very strong previous evidence for pathogenicity (ClinVar, DECIPHER). (SP) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. It has been identified in at least fifteen families with primary microcephaly and classified as pathogenic by diagnosistic laboratories in ClinVar (PMID: 29243349). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
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PM2_Supporting+PVS1+PM3_VeryStrong -
Criteria applied: PVS1,PM2,PM3_SUP -
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not provided Pathogenic:3
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This sequence change creates a premature translational stop signal (p.Lys2595Serfs*6) in the ASPM gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ASPM are known to be pathogenic (PMID: 19028728, 23611254). This variant is present in population databases (rs199422173, gnomAD 0.05%). This premature translational stop signal has been observed in individuals with autosomal recessive primary microcephaly (MCPH) (PMID: 19028728, 23611254, 29644084). ClinVar contains an entry for this variant (Variation ID: 21606). For these reasons, this variant has been classified as Pathogenic. -
Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 19770472, 26548919, 29644084, 31853109, 26691732, 23611254, 19028728, 32677750, 31589614, 34426522, 34402213) -
Inborn genetic diseases Pathogenic:1
The c.7782_7783delGA (p.K2595Sfs*6) alteration, located in exon 18 (coding exon 18) of the ASPM gene, consists of a deletion of 2 nucleotides from position 7782 to 7783, causing a translational frameshift with a predicted alternate stop codon after 6 amino acids. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. Reported in the homozygous state or in trans with a second pathogenic ASPM variant in multiple patients with autosomal recessive primary microcephaly (MCPH)(Nicholas, 2009; Passemard, 2009; Tan, 2014; Kraemer, 2016; Letard, 2017; Okamoto, 2018; Ahmed, 2019; Qi, 2020; Rasool, 2020; Duerinckx, 2021). Based on the available evidence, this alteration is classified as pathogenic. -
Microcephaly 1, primary, autosomal recessive Pathogenic:1
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ASPM-related disorder Pathogenic:1
The ASPM c.7782_7783delGA variant is predicted to result in a frameshift and premature protein termination (p.Lys2595Serfs*6). This variant has been reported, both in the homozygous and compound heterozygous states with a second truncating variant, in several patients affected with primary autosomal recessive microcephaly (Rasool et al. 2020. PubMed ID: 32677750; Nicholas et al. 2009. PubMed ID: 19028728; Tan et al. 2014. PubMed ID: 23611254; Passemard et al. 2016. PubMed ID: 26691732). This variant is reported in 0.046% of alleles in individuals of Latino descent in gnomAD. Frameshift variants in ASPM are expected to be pathogenic. This variant is interpreted as pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at