diagnostic manual, international classification of diseases (icd-10); in 1994, it was added to the fourth edition of the diagnostic and statistical manual of mental disorders (dsm-iv) as asperger's disorder. when hans asperger observed the autistic like symptoms and behaviors in boys through their social and communication skills, many professionals felt like asperger's syndrome was just a less severe form of autism. uta frith was one of these professionals who had this opinion. she was a professor at the institute of cognitive neuroscience of university college london, and was also an editor of autism and asperger syndrome. she said that individuals with asperger's had a "dash of autism". she was one of the first scientists who recognized autism and related disorders as the result of a condition of the brain instead of the outcome of detached parenting. contemporary less than two decades after the widespread introduction of as to english-speaking audiences, there are hundreds of books, articles and websites describing it; prevalence estimates have increased dramatically for asd, with as recognized as an important subgroup. however, questions remain concerning many aspects of as; whether it should be a separate condition from high-functioning autism is a fundamental issue requiring further study. the diagnostic validity of asperger syndrome is tentative, there is little consensus among clinical researchers about the usage of the term "asperger's syndrome", and there are questions about the empirical validation of the dsm-iv and icd-10 criteria. it is likely that the definition of the condition will change as new studies emerge and it will eventually be understood as a multifactorial heterogeneous neurodevelopmental disorder involving a catalyst that results in prenatal or perinatal changes in brain structures. there is uncertainty regarding the gender gap between males and females with as. a person with asperger's is often remarked as possessing masculine traits like emotional distance from the inability to empathize, and far more boys than girls are diagnosed with asperger's. most studies on the syndrome were derived from research on males, neglecting specific attention to females with as who often go misdiagnosed. for the most part, studies on girls with asperger's are anecdotal. changes in dsm-5 in 1994, asperger's syndrome was added to the american psychiatric association's diagnostic and statistical manual of mental disorders (dsm-iv). the dsm-v made a new, broad diagnosis in 2013 of autism spectrum disorder (asd). this category contains the previous individual diagnoses of autistic disorder, asperger's syndrome, and other related developmental disorders. asd is rated on levels of severity on a scale ranging from severe, through moderate, to mild based on clinical presentation. the levels are determined by the amount of support the individual requires.