8-22163508-AGT-CGA

Variant names:

• chr8-22163508-AGT-CGA
• NM_001317778.2:c.397_399delAGTinsCGA
• SFTPC p.Ser133Arg

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PS1

The NM_001317778.2(SFTPC):​c.397_399delAGTinsCGA​(p.Ser133Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SFTPC NM_001317778.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.00
• Publications: 0 publications found

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):

• SFTPC-related interstitial lung disease

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• surfactant metabolism dysfunction, pulmonary, 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Laboratory for Molecular Medicine, Genomics England PanelApp, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• chronic respiratory distress with surfactant metabolism deficiency

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PS1: Transcript NM_001317778.2 (SFTPC) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001317778.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SFTPC	NM_001317778.2	MANE Select	c.397_399delAGTinsCGA	p.Ser133Arg	missense	N/A	NP_001304707.1	P11686-2
	SFTPC	NM_001172410.2		c.397_399delAGTinsCGA	p.Ser133Arg	missense	N/A	NP_001165881.1	A0A0S2Z4Q0
	SFTPC	NM_001385653.1		c.397_399delAGTinsCGA	p.Ser133Arg	missense	N/A	NP_001372582.1	P11686-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SFTPC	ENST00000679463.1	MANE Select	c.397_399delAGTinsCGA	p.Ser133Arg	missense	N/A	ENSP00000505152.1	P11686-2
	SFTPC	ENST00000318561.7	TSL:1	c.397_399delAGTinsCGA	p.Ser133Arg	missense	N/A	ENSP00000316152.3	P11686-1
	SFTPC	ENST00000521315.5	TSL:1	c.397_399delAGTinsCGA	p.Ser133Arg	missense	N/A	ENSP00000430410.1	P11686-2

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		3.0

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr8-22021021;