Table 2.

Human claudin genes and transcript information

Gene	Localization	Introns	Transcript information	Protein size	Molecular weight	Pi
CLDN1	3q28	3	One form	211	22,744	8.41
CLDN2	Xq22	1	One form	230	24,549	8.47
CLDN3	7q11	0	One form	220	23,319	8.37
CLDN4	7q11	0	One form	209	22,077	8.38
CLDN5	22q11	1	Two variants: alternative splicing, coding unaffected	218	23,147	8.25
CLDN6	16p13	1	One form	220	23,292	8.32
CLDN7	17p13	3	One form	211	22,390	8.91
CLDN8	21q22	0	One form	225	24,845	9
CLDN9	16p13	1	One form	217	22,848	6.54
CLDN10	13q31	1	Two variants: alternative transcription start site, different amino termini	a: 226	24,251	9.24
				b: 228	24,488	8.32
CLDN11	3q26	2	One form	207	21,993	8.22
CLDN12	7q21	2	One form	244	27,110	8.8
CLDN14	21q22	2	Two variants: alternative splicing, coding unaffected	239	25,699	8.94
CLDN15	7q11	4	One form	228	24,356	5.61
CLDN16	3q28	4	One form	305	33,836	8.26
CLDN17	21q22	0	One form	224	24,603	9.8
CLDN18	3q34	4	Two variants: alternative transcription start site, different amino termini	a: 261	27,856	8.39
				b: 261	27,720	8.39
CLDN19	1p34	4	Two variants: alternative splicing, different carboxyl termini	a: 224	23,229	8.48
				b: 211	22,076	7.52
CLDN20	6q25	1	One form	219	23,515	6.98
CLDN21	11q23	0	One form	229	25,393	5.37
CLDN22	4q35	0	One form	220	25,509	5.37
CLDN23	8p23	0	One form	292	31,915	7.51
CLDN24	4q35	0	One form	205	22,802	4.87

The chromosomal localization, intron number, and transcript details are indicated for each of the claudin genes, together with the size (in amino acids), molecular weight (in Da), and isoelectric point (Pi) of their encoded proteins. CLDN10, CLDN18, and CLDN19 have two variants giving rise to slightly different proteins. Only the variants documented in GenBank are indicated and other variants may exist.