Down Syndrome Molly M. Zimmerman, B.A. University of Pittsburgh Department of Communication Science and Disorders key words: Down syndrome, orofacial anomalies
Author Information This lecture was authored by Molly M. Zimmerman, an advanced graduate student in the University of Pittsburgh Department of Communication Science and Disorders, School of Health and Rehabilitation Sciences. The presentation was prepared as a term assignment for the graduate course Cleft Palate and Craniofacial Disorders, taught by faculty member Ellen R. Cohn Ph.D. (firstname.lastname@example.org).
Author Information Continued Molly Zimmerman is a graduate of the University of Pittsburgh. Her clinical interests include adult rehabilitation as well as acute and sub-acute care. However, she would like to further explore her interests in child speech and language therapy. Molly’s interest in the lecture topic resulted from her desire to learn more about the causes and effects of Down syndrome.
What Will You Learn From This Presentation? • Causes of Down syndrome. • Characteristics of Down syndrome. • Medical concerns associated with Down syndrome. • Basic effects on speech.
Who Is Affected By Down Syndrome? • 1 child in every 800-1,100 births has Down syndrome. • 250,000 people in the U.S. have Down syndrome.
What Causes Down Syndrome? • Normally, each egg and sperm cell contains 23 chromosomes. • The union of these creates 23 pairs, or 46 total chromosomes. • Occasionally, an egg or sperm cell does not develop properly and contributes 24 chromosomes instead of 23.
What Causes Down Syndrome? (cont.) • Down syndrome results if the extra chromosome is number 21. • The features of Down syndrome result from having an extra chromosome 21 in each of the body’s cells. • Down syndrome is also referred to as Trisomy 21, because of the presence of three number 21 chromosomes.
What Does A Child With Down Syndrome Look Like? • May have eyes that slant upward. • Small ears that may fold over at the top. • Small mouth, making the tongue appear large. • Small nose, with a flattened nasal bridge. • Some babies may have short necks, small hands, and short fingers. • Adults are often short with unusually limber joints.
How Will Children With Down Syndrome Develop Compared To Other Children? • Children with Down syndrome can do most things that any young child can do, such as walking, talking, dressing, and being toilet trained, but usually develop later than other children. • Down syndrome usually results in some degree of mental retardation, the degree of which varies widely. However, many will learn to read and write. • Many people with Down syndrome hold supported employment, and frequently live semi-independently.
Special Health Problems Associated With Down Syndrome • Heart defects occur in 30-50%. • Intestinal malformations requiring surgery occur in 10-12%. • Visual and hearing impairments occur in > 50%. • Thyroid problems, adult onset leukemia, epilepsy, diabetes, and Alzheimer's occur more frequently.
Special Health Problems Associated With Down Syndrome (cont.) • Higher rate of infections due to compromised immune system and decrease in number of T cells. • Dry mouth caused by mouth breathing associated with upper respiratory infections. • Periodontal disease accelerated by increased number of infections.
What Extra Medical Care Should These Children Receive ? • Examination by a pediatric cardiologist and echocardiogram. • Regular vision and hearing exams. • Regular medical care including childhood immunizations.
What Problems Do Infections And Mouth Breathing Cause? • Higher incidence of periodontal disease. • Chronic dry mouth (xerostomia) and fissuring of tongue and lips. • Apthous ulcers, oral candida infections, and acute necrotizing ulcerative gingivitis.
Orofacial Features Frequently Associated with Down Syndrome • Underdevelopment or hypoplasia of midfacial region. • Smaller bridge of nose, bones of midface, and maxilla. • Open bite or class III malocclusion. • Tongue may protrude and appear too large.
Orofacial Features Frequently Associated With Down Syndrome (cont.) • Sides of the hard palate are abnormally thick, but it gives the appearance that the palate is narrow with a high vault (Pilcher, 1998). • Occasionally palatal cleft-like folds are found (Desai, 1997). • Reduced degree of muscle tone in lips and cheeks.
Effects Of Orofacial Features • Small nasal passage contributes to mouth breathing. • Less space in oral cavity for tongue effecting speech, mastication, and natural cleansing of teeth. • Force of tongue greater than force of teeth causing class III malocclusion.
Dental Anomalies In Individuals With Down Syndrome • Microdentia occurs in 35-55% (Desai, 1997). • Hypoplasia and Hypocalcification are common (Desai, 1997). • Congenitally missing teeth (partial anodontia) occur in 50% of people with Down syndrome (Desai, 1997). • Delay in the eruption of dentition (Desai, 1997).
Effects On Speech • Expressive language of children with Down syndrome is commonly more delayed than receptive language (Desai, 1997). • Contributing factors to expressive language delay include: mental deficiency, relatively large tongue in a small oral cavity, excessive salivation, poor oral closure, dry and thickened mucous, dental anomalies, hypotonia, hearing problems, aphasia. • Disordered articulation in children with down syndrome reflects a delay in speech development similar to that of normal children (Borsel, 1988).
Tongue Resection As A Treatment For Symptomatic Macroglossia • Tongue reduction surgery has no effect on the articulation of sounds (Parsons et al., 1987). • Partial glossectomy increases aesthetic appearance of speech, but has little or no effect on speech intelligibility (Klaiman et al., 1988; Margar-Bacal et al., 1987). • Tongue resection improved deglutition and reduced drooling (Siddiqui & Pensler, 1990).
Is There A Cure For Down Syndrome? • No, there is no cure. • It cannot be prevented • Scientists do not know why problems involving chromosome 21 occur. • Down syndrome is not caused by anything either of the parents did or did not do.
Who Has An Increased Risk Of Having A Baby With Down Syndrome? • Parent who already had one child with Down syndrome. • Parent who has a rearrangement involving chromosome 21. • Mother over 35 years old.
Can Down Syndrome Be Diagnosed Prenatally? • Yes, it can be diagnosed or more likely ruled out. • Alpha fetoprotein (AFP) blood test, a screening test, can be done around the 16th week of pregnancy. • Amniocentesis or chorionic villus sampling are the most reliable tests used, but should be used cautiously due to the risks associated with them.
A Quiz To Test Your Understanding 1. Is Down Syndrome caused by something the mother does during pregnancy? 2. Can Down Syndrome be prevented? 3. What factors contribute to mouth breathing? 4. What are some of the health problems associated with Down Syndrome?
Check Your Understanding 1. No. Nothing the mother (or father) does causes Down syndrome. 2. No. Down syndrome cannot be prevented. 3. Mouth breathing occurs due to small nasal passages and high incidence of respiratory infections. 4. Heart defects, intestinal malformations, vision and hearing impairments.
References • Desai, Sindoor (1997) Down Syndrome: A Review of the Literature. http://altonweb.com/cs/ downsyndrome/desai.html (7/20/99) • Klaiman, P., Witzel, M.A., Marger-Bascal, F., Munro, I.R., (1988). Changes in aesthetic appearance and intelligibility of speech after partial glossectomy in patients with Down syndrome. Plastic & Reconstructive Surgery,3, 403-8. • Margar-Bacal, F., Witzel, M.A., Munro, I.R., (1987). Speech intelligibility after partial glossectomy in children with Down’s syndrome. Plastic & Reconstructive Surgery, 1, 44-9.
References Continued • Parsons, CL., Iacono, TA., Rozner, L., (1987). Effect of tongue reduction on articulation in children with Down Syndrome. American Journal of Mental Deficiency,4, 328-32. • Pilcher, E., (1998). Dental care for the patient with Down syndrome. The Down Syndrome Educational Trust, 5(3), 111-116. • Siddiqui, A., Pensler, J.M., (1990). The efficacy of tongue resection in treatment of symptomatic macroglossia in the child. Annals of Plastic Surgery, 1, 14-7.
References Continued • The March of Dimes Birth Defects Foundation, (1997). Down Syndrome Public Health Educational Information Sheet. http://www.noah.cuny.edu/pregnancy/march_of_dimes/birth_defects/downsynd.html (7/20/99) • Van Borsel, J., (1988). An analysis of the speech of five Down’s syndrome adolescents. Journal of Communication Disorders, 5, 409-21.