Microtubular arrangement in 510 patients with normal ciliary ultrastructure
| Microtubular abnormalities considered to be within normal limits arrangement as observed in 510 patients with >200 profiles counted | Mean±SD % of ciliary cross-sections examined |
| Normal 9+2 arrangement | 91±8 |
| Disarranged microtubules | 2±2 |
| Extra microtubular doublet | 1±2 |
| Single microtubular doublet | <1±1 |
| Transposition of central pair | <1±1 |
| One of pair missing | 1±6 |
| Both of the central pair missing | 2±3 |
| Compound cilium | 1±1 |