Can crash dieting cause early onset of androgenetic alopecia?

It could lead to increased hair loss or accelerated male pattern baldness. I suggest seeing a hair loss expert now to evaluate and go over your condition and provide you information about your best treatment options. There are great non-invasive options like prp/progesterone and/or hair transplantation. See an expert. Best, Dr. Emer

Crash diet is  a frequent hair loss cause, the most important is avoiding crash diets for avoiding hair loss and hair damage. It will suggest you to see your primary care physician or specialist for helping you about your daily diet.

Anything that causes increased shedding can trigger acceleration of MPB. The term "accelerated follicular miniaturization from prolonged shedding (AFMPS) reflects the shortened hair cycles that occur with shedding in those who have a genetic predisposition to androgenetic alopecia (male balding). Any consumption of less than 1300 calories daily can trigger shedding. One can do very little to block shedding from crash dieting except consume more calories. The genetic hair loss however could potentially be slowed by standard therapy for genetic hair loss.

Crash dieting can induce the onset of genetic hair loss if you have the genes for it.  This may not be reasily reversible so see an expert in the field