I don't know if many people here would have ever heard about the concept of Broad Autism Phenotype (BAP). People who have BAP have significantly more autistic traits than the average person, but not quite enough to merit a diagnosis of ASD. BAP is the subclinical manifestation of ASD. It is common in close blood relatives of people diagnosed with ASD (such as parents and siblings.) It also occurs at a quite elevated rate in STEM professions. Probably a lot of people here have it. It is worth pointing out that it is not a disorder, it is a phenotype. The fundamental difference between BAP and ASD, is that in ASD the autistic traits impair functioning to the point that they become the legitimate focus of clinical attention, in BAP they don't reach the point of being impairing (or else, the impairments are so mild they are not worthy of clinical attention.) The boundary of whether ones functioning is so impaired as to be worthy of clinical attention is inherently a bit of a subjective judgement call, and is going to vary from clinician to clinician; BAP and ASD are on a continuum with each other, and there is no precise boundary between the two.

But actually other disorders have subclinical manifestations, not just ASD. Some researchers study subclinical ADHD, which has a similar relationship to ADHD as BAP has to ASD. Other study subclinical schizophrenia. And there is also study of subclinical OCD. (One big difference is that subclinical ASD has a distinctive name, whereas I don't think the subclinical manifestation of any other disorder has been given a distinctive name.)

Many people see ASD traits in themselves, even to the point of engaging in self-diagnosis, even if they don't actually meet the criteria for formal diagnosis. Yet, most of these people probably actually do have BAP, they just don't understand the BAP-vs-ASD distinction. Well, you could make the exact same point about OCD – many of the people who claim (even if somewhat light-heartedly) that they have OCD, but don't actually do so, may well actually have some degree of subclinical OCD, but they don't understand the subclinical vs clinical distinction.