Alpha-S1 Casein (CASEIN)
Alpha-S1 Casein protein level in goat's milk, cheese protein
Alpha-S1 Casein (CASEIN) is one of the four Casein proteins found in goat’s milk and the most important one for cheese making. A number of mutations in the gene that codes for the Alpha-S1 Casein protein can affect the amount of protein and fat produced which subsequently affects the quality of the milk for cheese making. Additional research has also demonstrated that low levels of Alpha-S1 Casein may be associated with reduced milk sensitivities for some people. The different variants demonstrated to affect casein protein levels can lead to high levels (A and B combinations), low levels (E,F, and N combinations), intermediate levels (A, B, E, F, N combinations), or no casein production (two copies of the O1 variant). The impact on protein levels involving certain variant combinations (O1 with other variants) has yet to be determined.
Reading Your Results
Test result explanation is based on the combined results for A, B, E, F, N, and O1 variants. Associated Alphas-S1 casein levels for different result combinations can be found in the following table:
| Variant | Casein Level | Result Explanation |
| A/A | High | A/A – High amount of Alpha S1 Casein |
| A/B | High | A/B – High amount of Alpha S1 Casein |
| B/B | High | B/B – High amount of Alpha S1 Casein |
| A/E | Intermediate | A/E – Intermediate amount of Alpha S1 Casein |
| A/F | Intermediate | A/F – Intermediate amount of Alpha S1 Casein |
| A/N | Intermediate | A/N – Intermediate amount of Alpha S1 Casein |
| B/E | Intermediate | B/E – Intermediate amount of Alpha S1 Casein |
| B/F | Intermediate | B/F – Intermediate amount of Alpha S1 Casein |
| B/N | Intermediate | B/N – Intermediate amount of Alpha S1 Casein |
| E/E | Low | E/E – Low amount of Alpha S1 Casein |
| E/F | Low | E/F – Low amount of Alpha S1 Casein |
| E/N | Low | E/N – Low amount of Alpha S1 Casein |
| F/F | Low | F/F – Low amount of Alpha S1 Casein |
| F/N | Low | F/N – Low amount of Alpha S1 Casein |
| N/N | Low | N/N – Low amount of Alpha S1 Casein |
| O1/O1 | None | O1/O1 – Will not produce Alpha S1 Casein |
| A/O1 | Unknown | A/O1 – Unknown amount of Alpha S1 Casein |
| B/O1 | Unknown | B/O1 – Unknown amount of Alpha S1 Casein |
| E/O1 | Unknown | E/O1 – Unknown amount of Alpha S1 Casein |
| F/O1 | Unknown | F/O1 – Unknown amount of Alpha S1 Casein |
| N/O1 | Unknown | N/O1 – Unknown amount of Alpha S1 Casein |
Additional Details
Inheritances
Complex Inheritance
Affected gene
CSN1S1
Chromosome
Ch. 6
Mutation
Variant B: 85987197 C>G (Gln>Glu), Variant E: 85995008 Ins-1, Variant F: Ins-2, Variant N: Del C (Stop), Variant O1: Del-4
Publication:
Rahmatalla SA, Arends D, Brockmann GA. Review: Genetic and protein variants of milk caseins in goats. Front Genet. 2022;13:995349. [PubMed: 36568379].
