Social interaction abnormalities

Following our characterization of NL3 R451C mutants, mice lacking NL4 were also found to exhibit autism-related behavioral abnormalities including social interaction abnormalities and ultrasonic vocalizations (Jamain et al., 2008). The functional consequences of NL4 deletion on synapses have yet to be determined. 

The clinical features must include delays or abnormalities in social interaction, language, or imaginative play before the age of 3 years. One or 2 years of relatively normal development can occur, although there is usually no period of clearly normal development. In some cases, regression in language, usually manifest as complete loss of speech after a child has acquired from 5 to 10 words, occurs. If there is a period of normal development, it cannot extend past the age of 3 years. 

Mice with abnormally poor or abnormally good cognitive abilities may produce aberrant behavior in this test (e.g., increased or decreased social interaction, respectively). To rule out this possibility, consider testing mice in some additional memory paradigms. Memory tests, such as the Morris Water Maze and OFT habituation, may be performed to assess cognitive functions in any abnormally behaving mouse. 

This boy has no history of any major medical illness that might have influenced his neurological development. He has a hypomelanotic skin condition (oculocutaneous albinism), but no vision or hearing impairments and no motor abnormalities. His developmental deficits are apparently restricted to communication, cognition, and social interactions. 

Some of the most supportive research includes studies of pulmonary physiology and response to respiratory challenges. Evidence exists that proximal socioenvironmental factors may interact with an underlying respiratory abnormality. From a developmental perspective, the evidence suggests that social separation may be one particularly important environmental factor in this regard. 

Malnutrition. In humans, it is difficult to say whether nutrition per se contributes to behavioral abnormalities, since conditions of malnutrition and a deprived social and emotional environment often coexist Studies have demonstrated the importanco of the mother-child relationship to learning and behavior, and malnutrition may adversely affecT this interaction. While the effects of malnutrition are uncortain, the following points deserve consideration ... 

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