| Gene | Description | Location | Gene Omim Number | Disease Omim Number |
| G6PC | GLUCOSE-6-PHOSPHATASE, CATALYTIC; G6PC | 17q21 | 613742 | 613742 |
| G6PD | GLUCOSE-6-PHOSPHATE DEHYDROGENASE; G6PD | Xq28 | 305900 | 305900 |
| GAA | GLUCOSIDASE, ALPHA, ACID; GAA | 17q25.2-q25.3 | 606800 | 606800 |
| GABRG2 | GAMMA-AMINOBUTYRIC ACID RECEPTOR, GAMMA-2; GABRG2 | 5q34 | 137164 | 137164 |
| GALC | GALACTOSYLCERAMIDASE; GALC | 14q24.3-q32.1 | 606890 | 606890 |
| GALT | GALACTOSE-1-PHOSPHATE URIDYLYLTRANSFERASE; GALT | 9p13 | 606999 | 606999 |
| GAMT | GUANIDINOACETATE METHYLTRANSFERASE; GAMT | 19p13.3 | 601240 | 601240 |
| GARS | GLYCYL-tRNA SYNTHETASE 1; GARS1 | 7p15 | 600287 | 601472 |
| GBA | GLUCOSIDASE, BETA, ACID; GBA | 1q21 | 606463 | 606463 |
| GCDH | GLUTARYL-COA DEHYDROGENASE; GCDH | 19p13.2 | 608801 | 608801 |
| GCK | GLUCOKINASE; GCK | 7p15-p13 | 138079 | 138079 |
| GFAP | GLIAL FIBRILLARY ACIDIC PROTEIN; GFAP | 17q21 | 137780 | 137780 |
| GHR | GROWTH HORMONE RECEPTOR; GHR | 5p13-p12 | 600946 | 600946 |
| GJB1 | GAP JUNCTION PROTEIN, BETA-1; GJB1 | Xq13.1 | 304040 | 304040 |
| GJB2 | GAP JUNCTION PROTEIN, BETA-2; GJB2 | 13q11-q12 | 121011 | 121011 |
| GK | GLYCEROL KINASE; GK | Xp21.3-p21.2 | 300474 | 300474 |
| GLA | GALACTOSIDASE, ALPHA; GLA | Xq22 | 300644 | 300644 |
| GLB1 | GALACTOSIDASE, BETA-1; GLB1 | 3p22.3 | 611458 | 611458 |
| GM2A | GM2-GANGLIOSIDOSIS, AB VARIANT | 5q31.3-q33.1 | 272750 | 613109 |
| GNPTAB | N-ACETYLGLUCOSAMINE-1-PHOSPHOTRANSFERASE, ALPHA/BETA SUBUNITS; GNPTAB | 12q23.3 | 607840 | 607840 |
| GNPTG | N-ACETYLGLUCOSAMINE-1-PHOSPHOTRANSFERASE, GAMMA SUBUNIT; GNPTG | 16p | 607838 | 607838 |
| GNS | N-ACETYLGLUCOSAMINE-6-SULFATASE; GNS | 12q14 | 607664 | 607664 |
| GPC3 | GLYPICAN 3; GPC3 | Xq26 | 300037 | 300037 |
| GUSB | MUCOPOLYSACCHARIDOSIS, TYPE VII; MPS7 | 7q21.11 | 253220 | 611499 |