They may also have troubles communicating non-verbally by using hand gestures, eye contact and facial expressions. The extent of their language usage is heavily influenced by their intellectual and social developments. The range of their skills can be very different and on opposite ends of a spectrum. Many children with autism develop some speech and language skills, but not like typically developing children, and with uneven progress.Asperger syndrome, which is classified under the broad umbrella term of autistic spectrum disorder, however, is not associated with language delay. Children diagnosed with Asperger syndrome have decent language skills but use language in different ways from others. They may not be able to understand the use of language devices, such as irony and humor, or conversation reciprocity between involved parties.Heritability
Genes have a very big influence in the presence of language impairments. Neurobiological and genetic mechanisms have a strong influence on late language emergence. A child with a family history of language impairments is more likely to have delayed language emergence and persistent language impairments. They are also 2 times more likely to be late talkers as compared to those with no such family history.Genetic abnormalities may also be a cause of language delays. In 2005, researchers found a connection between expressive language delay and a genetic abnormality: a duplicate set of the same genes that are missing in individuals with Williams-Beuren syndrome. Also so called XYY syndrome can often cause speech delay.Twins

Being a twin increases the chance of speech and language delays.
In addition, an inability to engage in social exchanges is a sign of language delay at all ages.Communicative deficits at specific ages and milestones might indicate language delay, including:

Not smiling at 3 months
Not turning the head toward sounds at 4 months
Not laughing or responding to sounds at 6 months
Not babbling at 9 months
Not pointing and using gestures at 12 months
Not producing more than 5 words at 18 months
Not producing more than 50 words at 24 months
Losing language and/or social skills after 36 monthsLater in life, important signs include:

A lack of speech
An inability to comprehend, process, or understand language presented to the child

Consequences of Language Delay
Language delay is a risk factor for other types of developmental delay, including social, emotional, and cognitive delay. Language delay can impact behavior, reading and spelling ability, and overall IQ scores. Some children may outgrow deficits in reading and writing while others do not. Other conditions associated with language delay include attention-deficit/hyperactivity disorder, autism spectrum disorder, and social communication disorder. Causes
Language delays are the most frequent developmental delays, and can occur for many reasons. A delay can be due to being a "late bloomer", "late talker", or a more serious problem. Such delays can occur in conjunction with a lack of mirroring of facial responses, unresponsiveness or unawareness of certain noises, a lack of interest in playing with other children or toys, or no pain response to stimuli. Socio-economic factors
Socio-economic status
Children from families of low educational level are more likely to have delays and difficulties in expressive language.