Asperger's Syndrome is a developmental disorder that can contribute to someones inceldom. People with Asperger's often experience difficulty socializing and blending in with normies. On the other hand, they are often exceptionally good at recognizing patterns and investigating certain topics with intense focus. People with Aspergers are often targets of pick up artists who scam them into buying into their ineffective programs. People with Asperger's famously suffer from the, "Attraction ambiguity problem".
Free Lesson for Aspies
Relationship between Autism Spectrum Disorder and Inceldom
Individuals with ASD are overrepresented in the Incel population as a whole. As a matter of fact, it could be reasonably surmised that the majority of men with the disorder are incel (but do not necessarily identify as such). A study(which included a review of the relevant literature relating to sexuality in people with ASD) published in the Dialogues in Clinical Neuroscience revealed that: 
- Individuals with more ASD symptoms reported lower sexual and relationship satisfaction
- Female ASD individuals were significantly younger at time of first sexual intercourse (then males with ASD)
- Autistic Males had much higher rates of sexual paraphilias (fetishes) then healthy controls and ASD females.
- Some evidence that women with ASD "might present less pronounced social and communication deficits and have special interests that are more compatible to the interests of their peer groups." (Study authors hypothesised that this was due to ASD women using better coping strategies then ASD men to "pass" as NT and imitate non-NT behavior, but examining this assertion from a blackpill lens would lead one to different conclusions.)
- Males with ASD were found to engage more in solitary sexual activities then the NT men in the sample, (16.1% of ASD men reported masturbating multiple times a day versus none of the NT men in the sample, and 14% of the NT men reported 'never' masturbating versus none of the ASD men reporting as such, for example)
- The amount of men with ASD who reported being in a relationship was 16% versus 82% of NT men and 46% of females with ASD. (Sample was comprised of people in their mid 30s on average.)
(Note: This figure is likely understating the number of ASD men who are incel,as there are a disproportionately higher number of homosexual/biseuxal men with ASD compared to NTs. The researchers lumped these into a single group.) This is also despite men with ASD reporting having higher levels of sexual desire and masturbating more frequently then NT men.
Extreme Male Brain Theory
A major controversial theory of the etiology (cause) of ASD is known as the extreme male brain theory. The theory first proposed by the world famous autism researcher from the University of Cambridge, Simon Baron-Cohen, states that the major cause of ASD is excessive exposure to androgens (male sex hormones) during prenatal development. Baron-Cohen does not claim that persons with ASD are more 'masculine' then neuro-typicals, a point often lost on laymen. Baron-Cohen merely asserts that this 'extreme' masculinity takes form in a deficit of empathy in ASD individuals, as well as an increase in their mental tendency to attempt to systemise information they receive from the external environment, which a major cause of the obsessional interests and social deficits displayed by those with the disorder.
It has also been proposed  that ASD represents a 'failed' male evolutionary mating strategy adaption, whereas the disorders that are similar in their etiology and pathology in some respects to autism such as Attention Deficit Hyperactivity Disorder(ADHD) and Anti-Social Personality Disorder (ASPD, commonly known as 'psychopathy') represent more beneficial adaptions in general , particularly the "dark triad" personality traits associated with ASPD, which are associated with a lower arousal threshold (less or no fear, desire for extreme stimulation, very low inhibition) and such are probably not 'trainable' but rather innate, contra r/TRP.
Relationship between Autism and Physical Attractiveness
In apparent contrast with the extreme male brain theory, there is some research indicating those (male and female) are more physically androgynous then NTs, possibly contributing to the higher incidence of inceldom among autists. A study in the Journal of Neurodevelopmental Disorders demonstrated that males with higher levels of 'autistic traits' were generally more physically feminine then males with lower levels of autistic traits and vice versa for females. 
The authors hypothesise that it is possible that those with ASD have more androgynous physical appearance but more male brains in regards to systemising/empathising. However their findings are directly contradicted by another study using similar methodology, which found that pre-pubescent children with ASD were more facially masculine and those with more severe symptoms tended towards being the most masculinized, utilizing 3D face tracking software. 
One of the explanations given by the authors of second study are that the first study examined adults, while theirs studied children. It is possible (speculation) that the social victimisation and exclusion suffered by many autists results in higher levels of cortisol and the subsequent lowering of testosterone that results from high cortisol levels, leading to a higher Cortisol/T ratio, which may result in a incomplete level of masculization of the face and body during puberty. Other explanations the authors of the series of studies gave were possible methodological errors in the first study, and since autism is not a single concrete disorder and set of universal symptoms but a 'spectrum' of behaviours and neurological differences, there is the possibility that the autists higher in social deficits are the more masculinized ones, whereas those higher in systemising and obsessive interests are not.
In accordance with the blackpill there is also some evidence that the social difficulties that those with ASD face do not only originate with the neurological traits of the disorder, but also with how those with the disorder are perceived by others. An article in the scientific journal Nature  presented a series of studies that demonstrated that when shown photos and clips of social interactions(filmed via first person with a go pro camera) of a group of ASD versus neurotypical individuals, ASD individuals were, as a group perceived as significantly less attractive, dominant, likeable, and fun to 'hang-out' with. They were however, perceived as roughly equally trustworthy, smart and good to live near compared to NT controls. Their findings also demonstrated that the "negative first impressions of adults with ASD occurred only when audio and/or visual information was present, and not when the transcript of their speech content was evaluated. This discrepancy suggests that social presentation style rather than the substantive content of social speech drove negative impression formation of individuals with ASD."