MODULE 1                                                                                      Autism                   

 

Use OMIM to discover the genetic components of Autism.

 

  1. Go to the following URL: www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=OMIM&itool=toolbar

 

  1. In the search OMIM for type Autism and then click on the Go button.

 

  1. When the new page pops up, write down the numbers the numbers that are on the first line. Ignore the % sign.

 

  1. Click on the number 209850 and read the description of Autism.

 

Read the information about autism and answer the following questions:

  1. What is autism?
  2. What are the characteristics exhibited by a child with autism?
  3. At what age does it begin to be obvious?
  4. List the chromosome designations (numbers or letters) that different forms of autism have been mapped to.
  5. What characteristics can be seen in the siblings of autistic children?
  6. In identical twins, if one child has the disorder, how often will the other child?
  7. Of every 10,000 births, how many children can be expected to have Autism.?
  8. What is the ratio of boys with Autism  to girls with Autism?
  9. What chemical is elevated in autistic children?
  10.  What two disease genes are found on either side of the gene for autism on chromosome 15?
  11.  Find 3 other sources of information about genetic components of autism and list the URL of each.
  12. Further Research: Why do Autism spectrum disorders as well as ADHD and PDD’s occur more often in males than females?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MODULE 1       Answer Sheet for Autism

 

  1. Autism is characterized by a three specific symptoms: limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypical, and ritualized patterns of interests and behavior.
  2. Patients with autism exhibit qualitative impairment in social interaction, as manifest by impairment in the use of nonverbal behaviors such as eye-to-eye gaze, facial expression, body postures, and gestures, failure to develop appropriate peer relationships, and lack of social sharing or reciprocity. Patients have impairments in communication, such as a delay in, or total lack of, the development of spoken language. In patients who do develop adequate speech, there remains a marked impairment in the ability to initiate or sustain a conversation, as well as stereotyped or idiosyncratic use of language. Patients also exhibit restricted, repetitive and stereotyped patterns of behavior, interests, and activities, including abnormal preoccupation with certain activities and inflexible adherence to routines or rituals.
  3. 3 years of age.
  4. Gene map locus 15q11-q13, 6p21.3-p21.2
  5. By analysis of 99 autistic probands and their families, Bolton et al. (1994) found an increased familial risk for both autism and more broadly defined pervasive developmental disorders (PPDs) in sibs, 2.9% and 2.9%, respectively, which is about 75 times higher than the risk in the general population

6.   In 40 pairs of twins, Ritvo et al. (1985) found a concordance rate for autism of 

       23.5% in dizygotic twins (4 of 17 pairs) and 95.7% in monozygotic twins (22 of

       23 pairs). In 27 same-sex pairs of monozygotic twins and 20 dizygotic twins,

       Bailey et al. (1995) found that 60% of monozygotic pairs were concordant for

       autism compared to 0% of dizygotic pairs. When they considered a broader

       spectrum of related cognitive or social abnormalities, 92% of monozygotic pairs

       were concordant compared to 10% of dizygotic pairs. The high concordance in

       monozygotes indicated a high degree of genetic control, and the rapid fall off of

       concordance in dizygotics suggested to Bailey et al. (1995) a multilocus, epistatic

       model.

  1.  Autism has a population prevalence of approximately 4 to 5 in 10,000.
  2.  The ratio is 4 male to 1 female.
  3.   Serotonin
  4.   Prader-Willi Syndrome, Cholestasis-lymphedema syndrome.