chr4-69957784-G-A

Variant names:

• chr4-69957784-G-A
• rs770073906
• NM_001891.4:c.165C>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001891.4(CSN2):​c.165C>T​(p.Ile55Ile) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,848 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CSN2 NM_001891.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.287
• Publications: 0 publications found

Genes affected

CSN2 (HGNC:2447): (casein beta) This gene is a member of the beta casein family. There are two types of casein protein, beta (encoded by this gene) and kappa, both of which are secreted in human milk. Beta casein is the principal protein in human milk and the primary source of essential amino acids for a suckling infant. Beta and kappa casein proteins acting together form spherical micelles which bind within them important dietary minerals, such as calcium and phosphorous. In addition, the C-terminal 14 aa of the protein has antimicrobial activity, especially in preterm milk, displaying antibacterial activity against S. aureus and Y. enterocolitica. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2020]

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001891.4. 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
	CSN2	NM_001891.4	MANE Select	c.165C>T	p.Ile55Ile	synonymous	Exon 6 of 8	NP_001882.1	P05814
	CSN2	NM_001302770.2		c.162C>T	p.Ile54Ile	synonymous	Exon 6 of 8	NP_001289699.1
	CSN2	NM_001385731.1		c.120C>T	p.Ile40Ile	synonymous	Exon 5 of 7	NP_001372660.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CSN2	ENST00000353151.4	TSL:1 MANE Select	c.165C>T	p.Ile55Ile	synonymous	Exon 6 of 8	ENSP00000341030.3	P05814

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460848 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726542

African (AFR) AF: 0.00 AC: 0 AN: 33442

American (AMR) AF: 0.00 AC: 0 AN: 44632

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39674

South Asian (SAS) AF: 0.00 AC: 0 AN: 86198

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53366

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5756

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111310

Other (OTH) AF: 0.00 AC: 0 AN: 60368

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	0.60
DANN	Benign	0.42
PhyloP100		0.29

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs770073906; hg19: chr4-70823502;