7-128398501-C-T

Variant names:

• chr7-128398501-C-T
• rs2288550
• NM_000883.4:c.987G>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Moderate BP6_Moderate BP7

The NM_000883.4(IMPDH1):​c.987G>A​(p.Leu329Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,458 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 Likely benign (★). Synonymous variant affecting the same amino acid position (i.e. L329L) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: IMPDH1 NM_000883.4 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 2.20
• Publications: 19 publications found

Genes affected

IMPDH1 (HGNC:6052): (inosine monophosphate dehydrogenase 1) The protein encoded by this gene acts as a homotetramer to regulate cell growth. The encoded protein is an enzyme that catalyzes the synthesis of xanthine monophosphate (XMP) from inosine-5'-monophosphate (IMP). This is the rate-limiting step in the de novo synthesis of guanine nucleotides. Defects in this gene are a cause of retinitis pigmentosa type 10 (RP10). Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2008]

IMPDH1 Gene-Disease associations (from GenCC):

• IMPDH1-related retinopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• Leber congenital amaurosis 11

  Inheritance: AD Classification: DEFINITIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), G2P
• retinitis pigmentosa 10

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• Leber congenital amaurosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.38).
• BP6: Variant 7-128398501-C-T is Benign according to our data. Variant chr7-128398501-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 1153028.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=2.2 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000883.4. 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
	IMPDH1	NM_000883.4	MANE Select	c.987G>A	p.Leu329Leu	synonymous	Exon 10 of 17	NP_000874.2
	IMPDH1	NM_001102605.2		c.957G>A	p.Leu319Leu	synonymous	Exon 9 of 16	NP_001096075.1	P20839-5
	IMPDH1	NM_001142576.2		c.888G>A	p.Leu296Leu	synonymous	Exon 9 of 16	NP_001136048.1	P20839-7

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IMPDH1	ENST00000338791.11	TSL:2 MANE Select	c.987G>A	p.Leu329Leu	synonymous	Exon 10 of 17	ENSP00000345096.6	P20839-6
	IMPDH1	ENST00000348127.11	TSL:1	c.879G>A	p.Leu293Leu	synonymous	Exon 8 of 15	ENSP00000265385.8	P20839-3
	IMPDH1	ENST00000955327.1		c.879G>A	p.Leu293Leu	synonymous	Exon 8 of 15	ENSP00000625386.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250902 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 6.84e-7 AC: 1 AN: 1461458 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727036

African (AFR) AF: 0.00 AC: 0 AN: 33470

American (AMR) AF: 0.0000224 AC: 1 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53280

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5744

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111804

Other (OTH) AF: 0.00 AC: 0 AN: 60372

GnomAD4 genome Cov.: 31

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	-	1	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.38
CADD	Benign	7.1
DANN	Benign	0.90
PhyloP100		2.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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: rs2288550; hg19: chr7-128038555;