8-22163096-T-C

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PM2PP5_Very_Strong

The NM_001317778.2(SFTPC):​c.218T>C​(p.Ile73Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,844 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

SFTPC
NM_001317778.2 missense

Scores

5
8
5

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:14

Conservation

PhyloP100: 2.22

Publications

120 publications found
Variant links:
Genes affected
SFTPC (HGNC:10802): (surfactant protein C) This gene encodes the pulmonary-associated surfactant protein C (SPC), an extremely hydrophobic surfactant protein essential for lung function and homeostasis after birth. Pulmonary surfactant is a surface-active lipoprotein complex composed of 90% lipids and 10% proteins which include plasma proteins and apolipoproteins SPA, SPB, SPC and SPD. The surfactant is secreted by the alveolar cells of the lung and maintains the stability of pulmonary tissue by reducing the surface tension of fluids that coat the lung. Multiple mutations in this gene have been identified, which cause pulmonary surfactant metabolism dysfunction type 2, also called pulmonary alveolar proteinosis due to surfactant protein C deficiency, and are associated with interstitial lung disease in older infants, children, and adults. Alternatively spliced transcript variants encoding different protein isoforms have been identified.[provided by RefSeq, Feb 2010]
SFTPC Gene-Disease associations (from GenCC):
  • surfactant metabolism dysfunction, pulmonary, 2
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae)
  • chronic respiratory distress with surfactant metabolism deficiency
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • SFTPC- related interstitial lung disease
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 12 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_001317778.2
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 8-22163096-T-C is Pathogenic according to our data. Variant chr8-22163096-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 13208.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
SFTPCNM_001317778.2 linkc.218T>C p.Ile73Thr missense_variant Exon 3 of 6 ENST00000679463.1 NP_001304707.1 P11686A0A0A0MTC9

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SFTPCENST00000679463.1 linkc.218T>C p.Ile73Thr missense_variant Exon 3 of 6 NM_001317778.2 ENSP00000505152.1 A0A0A0MTC9

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
249478
AF XY:
0.00
Gnomad AFR exome
AF:
0.00
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461844
Hom.:
0
Cov.:
33
AF XY:
0.00000138
AC XY:
1
AN XY:
727230
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53396
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1111996
Other (OTH)
AF:
0.00
AC:
0
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000826
AC:
1

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:14
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Surfactant metabolism dysfunction, pulmonary, 2 Pathogenic:9
Dec 20, 2020
Beijing Key Laboratry for Genetics of Birth Defects, Beijing Children's Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 13, 2020
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Neuberg Centre For Genomic Medicine, NCGM
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Ile73Thr variant has been previously reported in patients affected with interstitial lung disease (Liu et al, 2019). This previously reported SFTPC variant results in mistrafficking of the SFTPC pre-protein and has been identified in multiple individuals with surfactant protein C deficiency. This variant has been reported to the ClinVar database as Pathogenic. This variant is novel (not in any individuals) in 1000 Genomes. The amino acid Ile at position 73 is changed to a Thr changing protein sequence and it might alter its composition and physico-chemical properties. The variant is predicted to be damaging by both SIFT and PolyPhen2. The residue is conserved across species. The amino acid change p.Ile73Thr in SFTPC is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Pathogenic -

Jul 01, 2009
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Feb 27, 2023
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 30, 2023
Genomic Medicine Lab, University of California San Francisco
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 26, 2019
Johns Hopkins Genomics, Johns Hopkins University
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This previously reported SFTPC variant results in mistrafficking of the SFTPC pre-protein and has been identified in multiple individuals with surfactant protein C deficiency. We consider this variant to be pathogenic. -

Aug 28, 2017
Molecular Diagnostics Laboratory, M Health Fairview: University of Minnesota
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 20, 2023
3billion
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Predicted Consequence/Location: Missense variant Functional studies provide moderate evidence of the variant having a damaging effect on the gene or gene product (PMID: 21092132). In silico tool predictions suggest the damaging effect of the variant on the gene or gene product (REVEL: 0.73; 3Cnet: 0.37). The same nucleotide change resulting in the same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000013208 /PMID: 11893657).A different missense change at the same codon (p.Ile73Asn) has been reported to be associated with SFTPC related disorder (PMID: 31081264). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

not provided Pathogenic:3
Jan 04, 2018
Eurofins Ntd Llc (ga)
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 02, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 73 of the SFTPC protein (p.Ile73Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with childhood interstitial lung disease (PMID: 15293602, 15572558, 15756222). In at least one individual the variant was observed to be de novo. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 13208). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects SFTPC function (PMID: 21707890). For these reasons, this variant has been classified as Pathogenic. -

Jan 17, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Published functional studies demonstrate damaging effects including impaired uptake and degradation of surfactant phospholipid and accumulation of dysfunctional mitochondria (PMID: 21707890, 25344067); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 22461427, 26925580, 15572558, 32851322, 21707890, 25582472, 11893657, 25344067, 18643778, 21092132, 25553246, 20371530, 23701443, 15756222, 23926107, 25755194, 17597647, 15293602, 29569581, 31081264, 30630227, 31462320, 32095252, 28495692, 34134972, 33942430) -

Pulmonary fibrosis Pathogenic:1
Jun 09, 2022
Garcia Pulmonary Genetics Research Laboratory, Columbia University Irving Medical Center
Significance:Likely risk allele
Review Status:no assertion criteria provided
Collection Method:research

- -

Hereditary pulmonary alveolar proteinosis Pathogenic:1
Aug 26, 2022
Ambry Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.218T>C (p.I73T) alteration is located in exon 3 (coding exon 3) of the SFTPC gene. This alteration results from a T to C substitution at nucleotide position 218, causing the isoleucine (I) at amino acid position 73 to be replaced by a threonine (T). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This mutation is considered to account for approximately 30% of described mutations in the SFTPC gene. It was described in a large kindred with multiple individuals to co-segregate with lung disease of variable severity (Cameron, 2005) and has been reported as a de novo occurrence in several unrelated patients (Guillot, 2009). This amino acid position is not well conserved in available vertebrate species. In vitro studies have demonstrated that this alteration interferes with correct processing and routing of the final protein, as well as reduction in lipid degradation (Beers, 2011). The in silico prediction for this alteration is inconclusive. Based on the available evidence, this alteration is classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.18
BayesDel_addAF
Pathogenic
0.29
D
BayesDel_noAF
Pathogenic
0.18
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Benign
0.043
T;T;.;D;D;T;D
Eigen
Uncertain
0.22
Eigen_PC
Benign
0.22
FATHMM_MKL
Benign
0.61
D
LIST_S2
Uncertain
0.90
D;D;D;D;D;D;D
M_CAP
Pathogenic
0.82
D
MetaRNN
Uncertain
0.66
D;D;D;D;D;D;D
MetaSVM
Pathogenic
0.91
D
PhyloP100
2.2
PrimateAI
Uncertain
0.56
T
PROVEAN
Uncertain
-2.6
D;N;D;D;D;D;D
REVEL
Pathogenic
0.73
Sift
Uncertain
0.0030
D;D;D;D;D;D;D
Sift4G
Uncertain
0.0060
D;D;D;D;D;D;D
Polyphen
0.84, 0.55
.;.;P;.;P;.;.
Vest4
0.59
MVP
1.0
MPC
1.2
ClinPred
0.82
D
GERP RS
4.7
gMVP
0.83
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs121917834; hg19: chr8-22020609; API