Some children with certain language disorders may not properly process the sounds they hear, resulting in language impairments. The purpose of this study is to determine if deficits in auditory temporal processing-the way the brain analyzes the timing and patterns of sounds-are an inherited trait.

Families with auditory temporal processing deficits are sought in order to identify the genes responsible for auditory temporal processing deficits. Children and adults with a diagnosis or history of language impairment in the family and their family members-both affected and non-affected-are eligible for this two-part study. In Part 1, participants undergo a series of language tests and listening tests to measure various characteristics of how they perceive sound. In Part 2, they are interviewed about language disorders, learning disabilities, and other medical problems of family members. This information is used to construct a pedigree (family tree diagram) showing the pattern of inheritance of family traits. Study subjects whose pedigree indicates that language disorders may be hereditary in their family will provide either a small blood sample (1 to 2 tablespoons) or a tissue specimen obtained from a cheek swab (rubbing the inside of the cheek with a small brush or cotton swabs). The sample will be used to isolate DNA for genetic analysis.

Recent research implicates auditory processing deficits in the etiology of language impairments, but no standard methodology has been employed to determine whether auditory processing deficits are heritable traits. We are presently evaluating a battery of auditory processing measures in twins recruited from the general population. Our data indicates that performance on some of these tests has a significantly heritable component. We seek IRB approval to recruit these research subjects and their families into genetic studies to investigate the heritability of auditory temporal processing characteristics, and identify the causative genes.

• Auditory Perceptual Disorder
• Language Delay
• Language Disorder

• Bishop DV. Autism, Asperger's syndrome and semantic-pragmatic disorder: where are the boundaries? Br J Disord Commun. 1989 Aug;24(2):107-21. Review.
• Bishop DV. Is specific language impairment a valid diagnostic category? Genetic and psycholinguistic evidence. Philos Trans R Soc Lond B Biol Sci. 1994 Oct 29;346(1315):105-11. Review.
• Tomblin JB, Records NL, Buckwalter P, Zhang X, Smith E, O'Brien M. Prevalence of specific language impairment in kindergarten children. J Speech Lang Hear Res. 1997 Dec;40(6):1245-60.

• INCLUSION CRITERIA:

Diagnosis of auditory processing disorder (APD/CAPD) based on two or more standardized tests of auditory processing.

Age 6 to 85 years.

EXCLUSION CRITERIA:

Hearing loss with onset prior to age 20 years, defined as:

• Air conduction pure tone thresholds (250-8000 Hz) exceeding 20 dBHL
• Air-bone gaps, even in the presence of normal sensitivity, exceeding 10 dBHL
• Abnormal tympanogram

History of chronic/recurrent otitis media

History of ear surgery

History or diagnosis of central nervous system lesions/pathology, including:

• Intracranial tumors
• Cerebrovascular disease
• Degenerative CNS disorders
• CNS trauma
• Encephalitis
• Meningitis

Currently on medications capable of altering CNS function

History of treatment with ototoxic medication

History or diagnosis of:

• Attention deficit hyperactivity disorder (ADHD)
• Attention deficit disorder (ADD)

Non-English Speaking

English as a second language

Diagnosis of auditory neuropathy