Table 3.

Genetic loci demonstrating genome-wide association with maternal metabolic traits

Gene	Chromosome	Encoded protein	Protein function	Associated maternal trait	Associated metabolic traits in non-gravid populations
G6PC2	2	Glucose-6-phosphatase, catalytic, 2	Component of an integral membrane system that catalyses glucose-6- phosphate hydrolysis	Fasting glucose	Fasting glucose
GCKR	2	Glucokinase regulator	Regulatory protein that inhibits glucokinase by forming an inactive complex with the enzyme	Fasting C-peptide, fasting glucose	Lipid phenotypes, fasting glucose, 2-h glucose, fasting insulin, Type 2 diabetes
PCSK1	5	Proprotein convertase subtilisin/kexin type 1	Calcium-dependent serine endoprotease involved in proteolytic activation of several precursor proteins including proinsulin, pro- glucagon-like peptide 1 and pro-opiomelancortin, among others	Fasting glucose	Findings not consistent but associated with obesity-related traits, fasting plasma glucose, 2-h plasma glucose, and fasting and post-glucose proinsulin levels
PPP1R3B	8	Protein phosphatase 1, regulatory subunit 3B	Facilitates interaction of protein phosphatase 1 with enzymes of glycogen metabolism	Fasting C-peptide, fasting glucose	Lipid phenotypes, fasting glucose, C-reactive protein, Type 2 diabetes
HKDC1	10	Hexokinase domain containing 1	Structure consistent with a hexokinase, but function not yet defined	2-h glucose	Nominal association with 2-h glucose in a meta-analysis of over 40 000 individuals
MTNR1B	11	Melatonin receptor 1B	G-protein coupled receptor that is expressed on β-cells, binds melatonin and may antagonize insulin release	Fasting glucose, 1-h glucose	Fasting glucose, impaired fasting glucose, Type 2 diabetes, altered β-cell function, including decreased insulin release following oral and intravenous glucose
BACE2	21	β-site amyloid polypeptide cleaving enzyme 2	Not defined	Fasting C-peptide	None reported