Wat zijn Null mutaties?
| Variant | Plaats | Mutatie |
| Amersfoort | Tyr160→stop codon | |
| Bellingham | M1Val213 | Lys217-stop codon |
| Bredevoort | M1Val213 | C548G premature stopcodon 160 |
| *Brescia | M1Ala213 | E257-stop codon |
| *Cork | M1Val213 | CA deletion codon 180-premature stop codon |
| *Cosenza | M2 | Q305-stop codon |
| Bolton | M1Val213 | Pro362-C deletion + stop codon 373 |
| Clayton | M1Val213 | Pro 362-C insertion + stop codon 376 |
| Cairo | M1Ala213 | Lys259-stop codon |
| *Dublin | M1Val213 | T deletion 370-stop codon 373 |
| Granite falls | M1Val213 | Tyr160-C deletion + stop codon 160 |
| Hong kong | M2 | Leu318-TC deletion + stop codon 334 |
| Isola di procida | Unknown | 10kb deletion |
| Kowloon | M1Val213 | Tyr38-stop codon |
| *Lampedusa | M2 | G deletion codon 337-stop codon 338 |
| Lisbon | M1Val213 | Thr68-Ile |
| Ludwigshafen | M2 | Ile92-Asn |
| Soest | M1 (Ala213) | Thr102→delA, a TGA stop signal at codon 112 |
