NM_020806.5:c.1237+1_1237+2delGTinsTG

Variant names:

• chr14-67089076-GT-TG
• NM_020806.5:c.1237+1_1237+2delGTinsTG

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PVS1_Moderate

The NM_020806.5(GPHN):​c.1237+1_1237+2delGTinsTG variant causes a splice donor, intron change involving the alteration of a 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.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GPHN NM_020806.5 splice_donor, intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.24
• Publications: 0 publications found

Genes affected

GPHN (HGNC:15465): (gephyrin) This gene encodes a neuronal assembly protein that anchors inhibitory neurotransmitter receptors to the postsynaptic cytoskeleton via high affinity binding to a receptor subunit domain and tubulin dimers. In nonneuronal tissues, the encoded protein is also required for molybdenum cofactor biosynthesis. Mutations in this gene may be associated with the neurological condition hyperplexia and also lead to molybdenum cofactor deficiency. Numerous alternatively spliced transcript variants encoding different isoforms have been described; however, the full-length nature of all transcript variants is not currently known. [provided by RefSeq, Jul 2008]

GPHN Gene-Disease associations (from GenCC):

• sulfite oxidase deficiency due to molybdenum cofactor deficiency type C

  Inheritance: AR Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, G2P
• hereditary hyperekplexia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• complex neurodevelopmental disorder

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ENSG00000307479 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.04025974 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020806.5. 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
	GPHN	NM_020806.5	MANE Select	c.1237+1_1237+2delGTinsTG		splice_donor intron	N/A	NP_065857.1	Q9NQX3-2
	GPHN	NM_001377514.1		c.1297+1_1297+2delGTinsTG		splice_donor intron	N/A	NP_001364443.1
	GPHN	NM_001377515.1		c.1267+1_1267+2delGTinsTG		splice_donor intron	N/A	NP_001364444.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GPHN	ENST00000478722.6	TSL:1 MANE Select	c.1237+1_1237+2delGTinsTG		splice_donor intron	N/A	ENSP00000417901.1	Q9NQX3-2
	GPHN	ENST00000315266.9	TSL:1	c.1138+1_1138+2delGTinsTG		splice_donor intron	N/A	ENSP00000312771.5	Q9NQX3-1
	GPHN	ENST00000960384.1		c.1408+1_1408+2delGTinsTG		splice_donor intron	N/A	ENSP00000630443.1

Frequencies

GnomAD3 genomes Cov.: 32

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

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.2

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: chr14-67555793;