16-88809698-T-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP5 BP4

The NM_000485.3(APRT):c.543A>T(p.Ter181CysextTer?) variant causes a stop lost change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 34)
• Consequence: APRT NM_000485.3 stop_lost
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 2.73

Genes affected

APRT (HGNC:626): (adenine phosphoribosyltransferase) Adenine phosphoribosyltransferase belongs to the purine/pyrimidine phosphoribosyltransferase family. A conserved feature of this gene is the distribution of CpG dinucleotides. This enzyme catalyzes the formation of AMP and inorganic pyrophosphate from adenine and 5-phosphoribosyl-1-pyrophosphate (PRPP). It also produces adenine as a by-product of the polyamine biosynthesis pathway. A homozygous deficiency in this enzyme causes 2,8-dihydroxyadenine urolithiasis. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-88809698-T-A is Pathogenic according to our data. Variant chr16-88809698-T-A is described in ClinVar as [Pathogenic]. Clinvar id is 988026.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr16-88809698-T-A is described in Lovd as [Pathogenic].
• BP4: Computational evidence support a benign effect (BayesDel_addAF=-0.209337).. Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APRT	NM_000485.3	c.543A>T	p.Ter181CysextTer?	stop_lost	5/5	ENST00000378364.8
APRT	NM_001030018.2	c.*4A>T		3_prime_UTR_variant	5/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APRT	ENST00000378364.8	c.543A>T	p.Ter181CysextTer?	stop_lost	5/5	1	NM_000485.3	P1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 34

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Adenine phosphoribosyltransferase deficiency Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

APRT Deficiency Research Program of the Rare Kidney Stone Consortium, Landspitali, National University Hospital of Iceland

Sep 01, 2020

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.21	T
BayesDel_noAF	Benign	-0.54
Cadd	Benign	17
Dann	Benign	0.71
Eigen	Uncertain	0.67
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Uncertain	0.94	D
MutationTaster	Benign	1.0	N;N;N
Vest4		0.14
GERP RS		4.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8

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

LitVar

Other links and lift over

dbSNP: rs1909032484; hg19: chr16-88876106;