17-68537493-G-T

Variant names:

• chr17-68537493-G-T
• rs143893081
• NM_017565.4:c.1610C>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_017565.4(FAM20A):​c.1610C>A​(p.Ala537Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,754 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A537T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FAM20A NM_017565.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.430
• Publications: 0 publications found

Genes affected

FAM20A (HGNC:23015): (FAM20A golgi associated secretory pathway pseudokinase) This locus encodes a protein that is likely secreted and may function in hematopoiesis. A mutation at this locus has been associated with amelogenesis imperfecta and gingival hyperplasia syndrome. Alternatively spliced transcript variants have been identified. [provided by RefSeq, Aug 2011]

PRKAR1A (HGNC:9388): (protein kinase cAMP-dependent type I regulatory subunit alpha) cAMP is a signaling molecule important for a variety of cellular functions. cAMP exerts its effects by activating the cAMP-dependent protein kinase, which transduces the signal through phosphorylation of different target proteins. The inactive kinase holoenzyme is a tetramer composed of two regulatory and two catalytic subunits. cAMP causes the dissociation of the inactive holoenzyme into a dimer of regulatory subunits bound to four cAMP and two free monomeric catalytic subunits. Four different regulatory subunits and three catalytic subunits have been identified in humans. This gene encodes one of the regulatory subunits. This protein was found to be a tissue-specific extinguisher that down-regulates the expression of seven liver genes in hepatoma x fibroblast hybrids. Mutations in this gene cause Carney complex (CNC). This gene can fuse to the RET protooncogene by gene rearrangement and form the thyroid tumor-specific chimeric oncogene known as PTC2. A nonconventional nuclear localization sequence (NLS) has been found for this protein which suggests a role in DNA replication via the protein serving as a nuclear transport protein for the second subunit of the Replication Factor C (RFC40). Several alternatively spliced transcript variants encoding two different isoforms have been observed. [provided by RefSeq, Jan 2013]

PRKAR1A Gene-Disease associations (from GenCC):

• Acrodysostosis 1 with or without hormone resistance

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• acrodysostosis with multiple hormone resistance

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, Illumina
• Carney complex, type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), G2P
• pigmented nodular adrenocortical disease, primary, 1

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics
• acrodysostosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Carney complex

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial atrial myxoma

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• primary pigmented nodular adrenocortical disease

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.100310475).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_017565.4. 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
	FAM20A	NM_017565.4	MANE Select	c.1610C>A	p.Ala537Asp	missense	Exon 11 of 11	NP_060035.2	Q96MK3
	FAM20A	NM_001243746.2		c.1196C>A	p.Ala399Asp	missense	Exon 12 of 12	NP_001230675.1
	PRKAR1A	NM_001276290.1		c.973+7492G>T		intron	N/A	NP_001263219.1	P10644-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FAM20A	ENST00000592554.2	TSL:1 MANE Select	c.1610C>A	p.Ala537Asp	missense	Exon 11 of 11	ENSP00000468308.1	Q96MK3
	FAM20A	ENST00000226094.9	TSL:1	n.1288C>A		non_coding_transcript_exon	Exon 11 of 11
	FAM20A	ENST00000882126.1		c.1640C>A	p.Ala547Asp	missense	Exon 12 of 12	ENSP00000552185.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461754 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 727142

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86192

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111970

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.093
BayesDel_addAF	Benign	-0.083	T
BayesDel_noAF	Benign	-0.36
CADD	Benign	15
DANN	Uncertain	0.99
DEOGEN2	Benign	0.0068	T
Eigen	Benign	-0.56
Eigen_PC	Benign	-0.61
FATHMM_MKL	Benign	0.22	N
LIST_S2	Benign	0.54	T
M_CAP	Benign	0.021	T
MetaRNN	Benign	0.10	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.0	M
PhyloP100		-0.43
PrimateAI	Benign	0.35	T
Sift4G	Uncertain	0.0040	D
Polyphen		0.48	P
Vest4		0.15
MutPred		0.073		Loss of catalytic residue at G535 (P = 0.1351)
MVP		0.59
MPC		0.66
ClinPred		0.75	D
GERP RS		3.4
Varity_R		0.11
gMVP		0.35

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

Other links and lift over

dbSNP: rs143893081; hg19: chr17-66533634;