16-1790498-G-C

Position:

• chr16-1790498-G-C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_004970.3(IGFALS):​c.*102C>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000387 in 1,034,068 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 Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00012 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000025 (0 hom.)
• Consequence: IGFALS NM_004970.3 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.47

Genes affected

IGFALS (HGNC:5468): (insulin like growth factor binding protein acid labile subunit) The protein encoded by this gene is a serum protein that binds insulin-like growth factors, increasing their half-life and their vascular localization. Production of the encoded protein, which contains twenty leucine-rich repeats, is stimulated by growth hormone. Defects in this gene are a cause of acid-labile subunit deficiency, which maifests itself in a delayed and slow puberty. Three transcript variants encoding two different isoforms have been found for this gene. [provided by RefSeq, Mar 2009]

SPSB3 (HGNC:30629): (splA/ryanodine receptor domain and SOCS box containing 3) Predicted to be involved in proteasome-mediated ubiquitin-dependent protein catabolic process. Predicted to be located in cytosol. Predicted to be part of SCF ubiquitin ligase complex. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.82).
• BS1: Variant frequency is greater than expected in population afr. gnomad4_exome allele frequency = 0.0000249 (22/881836) while in subpopulation AFR AF= 0.000873 (19/21768). AF 95% confidence interval is 0.000571. There are 0 homozygotes in gnomad4_exome. There are 12 alleles in male gnomad4_exome subpopulation. Median coverage is 12. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IGFALS	NM_004970.3	c.*102C>G		3_prime_UTR_variant	2/2	ENST00000215539.4
IGFALS	NM_001146006.2	c.*102C>G		3_prime_UTR_variant	2/2
IGFALS	NR_027389.1	n.1974C>G		non_coding_transcript_exon_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IGFALS	ENST00000215539.4	c.*102C>G		3_prime_UTR_variant	2/2	1	NM_004970.3	P1
IGFALS	ENST00000415638.3	c.*102C>G		3_prime_UTR_variant	2/2	2
SPSB3	ENST00000569769.1	c.-13+3139C>G		intron_variant		3

Frequencies

GnomAD3 genomes AF: 0.000118 AC: 18 AN: 152114 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.000411

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000353 AC: 5 AN: 141730 Hom.: 0 AF XY: 0.0000261 AC XY: 2 AN XY: 76758

Gnomad AFR exome AF: 0.000734

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS 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: 0.0000249 AC: 22 AN: 881836 Hom.: 0 Cov.: 12 AF XY: 0.0000264 AC XY: 12 AN XY: 453930

Gnomad4 AFR exome AF: 0.000873

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000162

Gnomad4 OTH exome AF: 0.0000243

GnomAD4 genome AF: 0.000118 AC: 18 AN: 152232 Hom.: 0 Cov.: 33 AF XY: 0.000107 AC XY: 8 AN XY: 74438

Gnomad4 AFR AF: 0.000409

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.000174

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Short stature due to primary acid-labile subunit deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.82
CADD	Benign	2.4
DANN	Benign	0.62

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: rs886051774; hg19: chr16-1840499;