Table 1. Results of glucose excretion studies and mutation analysis in patients with isolated glucosuria and their family members. Index patients with severe glucosuria and SGLT2 mutations on both chromosomes are indicated by boldfacea

Family-member (initials)Glucose excretion (g/1.73 m2 per d; normal 0.13–0.32b)Allele 1Allele 2
a wt, wild type; fs, frameshift; n.d., not determined; Ø, no glucosuria by dipstick method.
b According to ref 11; this normal range corresponds to 0.72–1.8 mmol/1.73 m2 per d.
c Consanguinity of the parents.
d Siblings.
e At elevated blood glucose concentrations as a result of type 2 diabetes.
f Associated by N654S, which we consider to be a polymorphism because of its location in transmembrane region 14. This α-helical transmembranous domain has been shown not to be essential for proper function of SGLT. It is missing in some members of the SGLT family, and in vitro deletion does not eliminate sugar transport (40,41). When investigating anonymous blood samples, N654S was detected in 1 of 80 chromosomes.
g Identical twins.
h Repeatedly positive when tested by dipstick.
01–1 index case (MP)126–162.2P 324 fs…347 XP 324 fs…347 X
- 2 fatherc1.1P 324 fs…347 Xwt
- 3 motherc2.7wtP 324 fs…347 X
- 4 sister0.40n.d.n.d.
- 5 brother0.31n.d.n.d.
- 6 sister0.05n.d.n.d.
02–1 index case (BMW)73.6G 272 RG 272 R
- 2 fatherc0.8G 272 Rwt
- 3 motherc0wtG 272 R
- 4 brother0.11G 272 Rwt
03–1 index case (AH)50.6–51.3IVS 7 + 5 g > aIVS 7 + 5 g > a
- 2 fatherc0.15IVS 7 + 5 g > awt
- 3 motherc0.02wtIVS 7 + 5 g > a
- 4 sibling0.03IVS 7 + 5 g > awt
- 5 sibling0IVS 7 + 5 g > awt
- 6 sibling0.09IVS 7 + 5 g > awt
04–1 index cased (PC)21.3IVS 7 + 5 g > aL 307 P
- 2 index cased (IC)28.5IVS 7 + 5 g > aL 307 P
- 3 fatherØwtL 307 P
- 4 motherØIVS 7 + 5 g > awt
05–1 index case (AK)43.0G 449 DG 449 D
- 2 motherc0.24G 449 Dwt
- 3 sibling0.07wtG 449 D
06–1 index case (OY)68.7W 440 XW 440 X
- 2 fatherc0.21W 440 Xwt
- 3 motherc0.12wtW 440 X
- 4 sibling0.19W 440 Xwt
- 5 sibling0.61W 440 Xwt
- 6 sibling0.27W 440 Xwt
07–1 index case (KN)20.8W 487 C, Δ488–506?
- 2 father0.38W 487 C, Δ488–506wt
- 3 mother0.29wt?
08–1 index case (NB)0.6Δ651–64wt
- 2 father10.4eΔ651–64wt
- 3 mother0.03wtwt
- 4 sibling0.04wtwt
09–1 index case (CE)38.8R 368 WR 368 W
- 2 fatherc0.99R 368 Wwt
- 3 motherc0.15wtR 368 W
- 4 sibling0wtwt
10–1 index case (SG)2.3–4.5Q 168 fs…186 Xwt
- 2 father0.17Q 168 fs…186 Xwt
- 3 mothern.d.wtwt
- 4 siblingn.d.wtwt
- 5 grandfather (p)12.3eQ 168 fs…186 Xwt
- 6 grandmother (p)n.d.wtwt
11–1 index case (FdS)0.75IVS 7 + 5 g > awt
- 2 fatherØwtwt
- 3 mother0.4IVS 7 + 5 g > awt
- 4 grandmother (m)ØIVS 7 + 5 g > awt
12–1 index case (CS)14.6IVS 7 + 5 g > aK 311 R
- 2 mother3.7IVS 7 + 5 g > awt
- 3 sibling4.4IVS 7 + 5 g > awt
- 4 sister of grandfather (m)1.7IVS 7 + 5 g > awt
13–1 index case (CP)5.9F 72 Lfwt
- 2 husbandØwtwt
- 3 mother0.23F 72 Lfwt
- 4 son1.3F 72 Lfwt
- 5 paternal cousin3.5F 72 Lfwt
14–1 index case (SP)2.8wtwt
- 2 father0.07wtwt
- 3 mother0.04wtwt
- 4 sister0.01wtwt
- 5 grandmother (p)0.01wtwt
- 6 grandfather (m)0.04wtwt
- 7 grandmother (m)0.01wtwt
15–1 index caseg (FS)202R 137 HΔ385–8
- 2 index caseg (MS)79.8R 137 HΔ385–8
- 3 father0.24–0.36R 137 Hwt
- 4 mother0.15–0.47wtΔ385–8
16–1 index case (GS)1.8T 51 Pwt
- 2 father0.07wtwt
- 3 mother1.4T 51 Pwt
17–1 index case (UU)30.1–92.4T 543 PT 543 P
- 2 fathercn.d.T 543 Pwt
- 3 mothercn.d.wtT 543 P
18–1 index case (AC)1.6–5.0n.d.n.d.
- 2 father4.8V 105 Mwt
19–1 index case (SK)8.0–16.7wtwt
20–1 index case (AM)31.7Y 150 HR 499 C
- 2 father0.16hwtR 499 C
- 3 mother0.05Y 150 Hwt
21–1 index case (NZ)1.2F 453 Lwtf
- 2 father0.13F 453 Lwt
- 3 mother0.04wtwtf
22–1 index case (RW)1.9Δ385–8wt
- 2 father0Δ385–8wt
- 3 mother0wtwt
23–1 index case (LT)0.75IVS 7 + 5 g > awt
- 2 father0.23wtwt
- 3 mother0.87IVS 7 + 5 g > awt
- 4 sibling1.5IVS 7 + 5 g > awt
- 5 sibling0.82IVS 7 + 5 g > awt