Table 2. Human β-tubulin isotypes.

Gene	Full name	Alternative name	Locus	Transcript variants NCBI Reference Sequence	Number of protein-coding transcribed from this gene https://www.proteinatlas.org/	Tissue-Expression	Associated Human Diseases
TUBB	Tubulin beta class I	Tubb5	6p21.33	1 - NM_001293212.1 2 - NM_178014.3 3 - NM_001293213.1 4 - NM_001293214.1 5 - NM_001293215.1 6 - NM_001293216.1	4 (49.7, 41.7, 47.8, 41.7 kDa)	Ubiquitous	Cortical dysplasia, complex, with other brain malformations
TUBB1	Tubulin beta 1 class VI	---	20q13.32	1 - NM_030773.3	1 (50.3 kDa)	Enriched in platelets and megakaryocytes	Autosomal dominant macrothrombocytopenia
TUBB2A	Tubulin beta 2A class IIa	TUBB2	6p25.2	1 - NM_001069.2 2 - NM_001310315.1	1 (49.9 kDa)	Ubiquitous	Cortical dysplasia with other brain malformations
TUBB2B	Tubulin beta 2B class IIb	MGC8685	6p25.2	1 - NM_178012.4	1 (50.0 kDa)	Ubiquitous	Asymmetric polymicrogyria
TUBB3	Tubulin beta 3 class III	beta-4	16q24.3	1 - NM_006086.3 2 - NM_001197181.1	8 (50.4, 42.4, 5, 20.7, 10.8, 13.6, 18.3, 16.4 kDa)	Ubiquitous	Congenital fibrosis of the extraocular muscles type 3
TUBB4A	Tubulin beta 4A class IVa	TUBB4	18p13.3	1 - NM_001289123.1 2 - NM_001289127.1 3 - NM_006087.3 4 - NM_001289129.1 5 - NM_001289130.1 6 - NM_001289131.1	11 (49.6, 11.8, 17.6, 16.6, 10.6, 11.7, 17.8, 17.4, 12.2, 7.8, 15.8 kDa)	Ubiquitous	Hypomyelinating leukodystrophy-6 and autosomal dominant torsion dystonia-4
TUBB4B	Tubulin beta 4B class IVb	TUBB2C	9q34.3	1 - NM_006088.5	1 (49.8 kDa)	Ubiquitous	ND
TUBB6	Tubulin beta 6 class V	MGC4083	18p11.21	1 - NM_032525.2 2 - NM_001303524.1 3 - NM_001303525.1 4 - NM_001303526.1 5 - NM_001303527.1 6 - NM_001303528.1 7 - NM_001303529.1 8 - NM_001303530.1	10 (49.6, 11.8, 17.6, 16.6, 10.6, 11.7, 17.8, 17.4, 12.2, 7.8, 15.8 kDa)	Ubiquitous	ND
TUBB8	Tubulin beta 8 class VIII	bA631M21.2	10p15.3	1 - NM_177987.2	5 (49.8, 7.8, 45.5, 13, 45.7 kDa)	Ubiquitous low	Defects in this gene are a cause of oocyte maturation defect 2 and infertility

ND: Not described.