NM_017613.4:c.1047-9A>G

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM2PP5_Very_Strong

The NM_017613.4(DONSON):​c.1047-9A>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000471 in 1,613,826 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000048 ( 0 hom. )

Consequence

DONSON
NM_017613.4 intron

Scores

2
Splicing: ADA: 0.6194
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 0.388

Publications

3 publications found
Variant links:
Genes affected
DONSON (HGNC:2993): (DNA replication fork stabilization factor DONSON) This gene lies downstream of the SON gene and spans 10 kb on chromosome 21. The function of this gene is unknown. [provided by RefSeq, Jul 2008]
DONSON Gene-Disease associations (from GenCC):
  • microcephaly, short stature, and limb abnormalities
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 21-33582064-T-C is Pathogenic according to our data. Variant chr21-33582064-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 431414.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DONSONNM_017613.4 linkc.1047-9A>G intron_variant Intron 6 of 9 ENST00000303071.10 NP_060083.1 Q9NYP3-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DONSONENST00000303071.10 linkc.1047-9A>G intron_variant Intron 6 of 9 1 NM_017613.4 ENSP00000307143.4 Q9NYP3-1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152190
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000882
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000477
AC:
12
AN:
251390
AF XY:
0.0000368
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000967
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000479
AC:
70
AN:
1461636
Hom.:
0
Cov.:
31
AF XY:
0.0000426
AC XY:
31
AN XY:
727144
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39672
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86252
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000567
AC:
63
AN:
1111828
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60382
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.491
Heterozygous variant carriers
0
4
8
13
17
21
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152190
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74360
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41448
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000882
AC:
6
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000900
Hom.:
0
Bravo
AF:
0.0000227

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Microcephaly, short stature, and limb abnormalities Pathogenic:3
Apr 14, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: DONSON c.1047-9A>G alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 computational tools predict no significant impact on normal splicing. However, multiple publications report the variant to have an impact on splicing, specifically a reduction in DONSON transcript levels compared to normal controls as well as significantly increased retention of intron 6 (Reynolds_2017, Evrony_2017). The variant allele was found at a frequency of 4.8e-05 in 251390 control chromosomes. c.1047-9A>G has been reported in the literature in multiple individuals affected with Microcephaly, Short Stature, And Limb Abnormalities including several members of the same family in the homozygous state (Reynolds_2017, Evrony_2017). These data indicate that the variant is very likely to be associated with disease. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as pathogenic, and one laboratory classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as pathogenic. -

Aug 05, 2017
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Dec 20, 2023
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Microcephaly-micromelia syndrome Pathogenic:2
Aug 05, 2017
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

-
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:2
Nov 21, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports a deleterious effect on splicing; This variant is associated with the following publications: (PMID: 37644014, 34426522, 29760432, 31191207, 28191891, 32552793, 28630177, 34645488, Michel2024[CaseReport]) -

Mar 12, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 6 of the DONSON gene. It does not directly change the encoded amino acid sequence of the DONSON protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or disrupted protein product. This variant is present in population databases (rs779149681, gnomAD 0.01%). This variant has been observed in individuals with DONSON-related conditions (PMID: 28191891, 28630177). ClinVar contains an entry for this variant (Variation ID: 431414). Studies have shown that this variant alters DONSON gene expression (PMID: 28191891). Studies have shown that this variant results in retention of intron 6 and introduces a premature termination codon (PMID: 28630177). The resulting mRNA is expected to undergo nonsense-mediated decay. For these reasons, this variant has been classified as Pathogenic. -

DONSON-related disorder Pathogenic:1
May 14, 2024
PreventionGenetics, part of Exact Sciences
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The DONSON c.1047-9A>G variant is predicted to interfere with splicing. This variant has been reported in the compound heterozygous and homozygous states in patients with microcephalic dwarfism or microcephaly micromelia syndrome, and segregates with the disease in affected family members (Reynolds et al. 2017. PubMed ID: 28191891; Evrony et al. 2017. PubMed ID: 28630177; Family 15DG2154 in Table S1, Maddirevula. 2020. PubMed ID: 32552793; Shamseldin et al. 2021. PubMed ID: 34645488). This variant is predicted to alter splicing based on available splicing prediction programs (Alamut Visual v2.11). In addition, RNA studies suggest that this variant causes intron 6 retention (Evrony et al. 2017. PubMed ID: 28630177). This variant is reported in 0.011% of alleles in individuals of European (Non-Finnish) descent in gnomAD. This variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.59
CADD
Benign
11
DANN
Benign
0.84
PhyloP100
0.39
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Mutation Taster
=8/92
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.62
SpliceAI score (max)
0.51
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.51
Position offset: -9

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs779149681; hg19: chr21-34954370; API