Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1PM2PM4_SupportingPP3_Moderate
The NM_000352.6(ABCC8):c.4117_4119delAAG(p.Lys1373del) variant causes a conservative inframe deletion, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).
ABCC8 (HGNC:59): (ATP binding cassette subfamily C member 8) The protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the MRP subfamily which is involved in multi-drug resistance. This protein functions as a modulator of ATP-sensitive potassium channels and insulin release. Mutations in the ABCC8 gene and deficiencies in the encoded protein have been observed in patients with hyperinsulinemic hypoglycemia of infancy, an autosomal recessive disorder of unregulated and high insulin secretion. Mutations have also been associated with non-insulin-dependent diabetes mellitus type II, an autosomal dominant disease of defective insulin secretion. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jul 2020]
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
Variant summary: ABCC8 c.4117_4119delAAG (p.Lys1373del) results in an in-frame deletion that is predicted to remove one amino acid from the encoded protein. The variant was absent in 251224 control chromosomes (gnomAD). c.4117_4119delAAG has been reported in the literature in a heterozygous individual affected with Dominant CH. These data do not allow any conclusion about variant significance. This publication also reports experimental evidence evaluating an impact on protein function, finding that the variant results in a substantial reduction in channel function. The following publication has been ascertained in the context of this evaluation (PMID: 26431509). ClinVar contains an entry for this variant (Variation ID: 553439). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Maturity onset diabetes mellitus in young Uncertain:1
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Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: research
Mutations in ABCC8 gene are associated with both neonatal diabetes mellitus as well as MODY. Patients with this mutation may have a better response to sulfonylureas. However, no sufficient evidence is found to ascertain the role of this particular variant (rs1554905655) in MODY yet. -
Transitory neonatal diabetes mellitus Uncertain:1
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Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: research
Mutations in ABCC8 gene are associated with both neonatal diabetes mellitus as well as MODY. Patients with this mutation may have a better response to sulfonylureas. However, no sufficient evidence is found to ascertain the role of this particular variant (rs1554905655) in neonatal diabetes yet. -