Today’s guest post on genetic syndromes comes from Rachel Nortz, who is contributing a post on the Down Syndrome.
Down Syndrome is a genetic disorder that is characterized by all or part of a third copy of the 21st chromosome. There are three different forms of Down syndrome: trisomy 21, translocation, and mosaicism. Trisomy 21 is the most common form of Down syndrome. This occurs when the 21st chromosome pair does not split properly and the egg or sperm receives a double-dose of the extra chromosome. Translocation (3-4% have this type) is the result of when the extra part of the 21st chromosome becomes attached (translocated) onto another chromosome. Mosaicism is the result of an extra 21st chromosome in only some of the cells and this is the least common type of Down syndrome.
Persons with Down syndrome typically have differences in physical growth and development, facial features, and severe intellectual disabilities. Down syndrome occurs in one out of every 691 births according to the CDC, making it the most commonly occurring genetic condition in the United States. Currently there are more than 400,000 people living with Down syndrome.
Down syndrome is not often mistaken for any other genetic defect, as Down syndrome is diagnosed prenatally using a various screenings or diagnostic procedures. An ultrasound or blood test can be completed on the pregnant mother to estimate the risk of a child having Down syndrome. A chorionic villus sampling (CVS) and/or amniocentesis are most common procedures to diagnose Down syndrome. Both procedures do carry risk of spontaneous termination (1% chance), but are almost 100% accurate in diagnosing Down syndrome. Screenings and diagnostic procedures for Down syndrome are now commonplace to the majority of pregnant women. Down syndrome can also be diagnosed at birth based on physical characteristics of the baby and via a blood test that specifically looks at the chromosomes of the child.
Males versus Females
Down syndrome occurs evenly in both males and females. Males tend to be sterile while women are capable of having babies. If the mother with Down syndrome chooses to have children, there is a 50% change that her child will also have Down syndrome.
Common physical characteristics of Down syndrome are: low muscle tone, small stature, an upward slant to the eyes and a single deep crease across the center of the palm. Individuals with Down syndrome may also present with a flat appearing face, small head, flat bridge on the nose, small mouth causing the tongue to appear large, extra fold of skin in the inside corner of each eye (epicanthal folds), rounded cheeks, misshapen ears, small wide hands, malformed fifth finger, unusual creases on the soles of the feet, overly-flexible joints, and shorter than normal height. However it should be stated that each person with Down syndrome may manifest these characteristics to varying degrees or not at all. Babies with Down syndrome develop at slower rates then normal children. The muscles of babies with Down syndrome ware hypotonic and thus will sit-up, crawl and walk at a much later age than same aged peers.
There are several medical concerns with individuals with Down syndrome. There are common clinical conditions such as congenital heart disease (30-50% occurrence), ear nose and throat disorders, hearing and vision deficits, endocrine disorders, neurological disorders and gastrointestinal disorders (5-7% occurrence). It is very common for infants to have congenital heart defects. Some common cardiac defects are atrial septal, patent ductus arteriosus, and ventricular septal defects. Infants with Down syndrome also exhibit gastrointestinal malformations that most likely will require surgery. Children with Down syndrome have a high incidence rate of developing upper respiratory problems such as asthma and bronchitis, otitis media, vision loss, dental malformations and seizures. Obstructive sleeping disorders, such as noisy breathing and sleep apnea are common. It is also common to develop pneumonia, certain kidney disorders, and 20 percent greater chance of developing leukemia.
There are also health issues which adolescents with Down syndrome demonstrate: increased weight gain, skin infections and psychiatric disorders. The increased weight gain can be contributed to reduced physical activity, an increase in food intake and thyroid issues. An increase in weight gain contributes to skin infections that can develop into abscesses. Therefore, proper hygiene is crucial during the adolescent period. Clinical depression is also common during the adolescent stage. Later in life people with Down syndrome are prone to Alzheimer’s disease.
Typically children with Down syndrome are developmentally delayed and thus their social development is delayed as well. Their behavior changes will occur later than the typically developing child. For instance, temper tantrums will develop around 3-4 years of age versus the typically developing child who demonstrates temper tantrums around 2-3 years of age. The family environment will greatly influence social abilities of children with Down syndrome. Positive family interaction is crucial to the social development of children with Down syndrome by giving them supportive social interactions. Adolescents with Down syndrome will demonstrate lower maturity levels than their peers due to cognitive delays. Each person with Down syndrome will display different temperaments, behaviors and not all children with Down syndrome are “happy” as a common stereotype suggests.
People with Down syndrome typically have some form of delay in cognitive development ranging from mild to moderate severity.
Speech and Language Issues and Applicable Interventions
Children who have Down syndrome will usually experience challenges with speech and language skills to varying degrees across their lifespan. The speech and language skills of a child with Down syndrome are considered delayed and not different. There are no specific speech and language skills that are only seen in children with Down syndrome. All of their deficits in speech and language can be seen in other children who do no have Down syndrome.
Children with Down syndrome have speech and language skills that are affected by anatomical and physiological differences. Feeding may be a significant difficulty for infants with Down syndrome due to oral-motor deficits. Most babies may need assistance in developing a strong suck and swallow pattern. The size of the nipple, and the hole can be modified for the child. Children with Down syndrome need to have their bodies and their mouths prepared for feeding by increasing their alertness and awareness. Some students may also have hypo-sensitive oral cavities and thus poorly chew food, overstuff mouth, and be messy eaters. Other children may be hyper-sensitive causing defensiveness when eating, refusal to eat or picky eaters.
Expressive language develops slowly, difficulty with this skill increases with age. Due to the delay in expressive language toddlers with Down syndrome may have delayed babbling and may be more inclined to use gestures of sign language instead of speech. Age of first word production is delayed until an average of 2 years of age. Once the children can use words they may experience difficulty with intelligibility and fluency; this is due to a structure and function problem with their articulators. If the child experiences frustration with expressive language the use of supplemental AAC device may aid in alleviating the stress.
Children with Down syndrome usually have better receptive skills and thus can comprehend more language than they can produce. However children with Down syndrome do experience difficulty with understanding abstract concepts. A child’s expressive language may seem to reach a plateau at an age six developmental level. However, it should be noted that development of language in children with Down syndrome is not consistent; there are period of plateau and period of improvement. Syntax is also a weakness for children with Down syndrome; they produce shorter sentences and have difficulty with grammar. A child with Down syndrome will have a normally developing noun vocabulary; however acquisition of verbs is often delayed. Pragmatic skills may also be an area of difficulty for the child. For example: asking for help, using appropriate greetings, asking for information, etc.
With the appropriate assessments and early intervention techniques from a team of experts children with Down syndrome will improve their speech and language skills. Depending on their severity level usually a child with Down syndrome will be able to develop effective communication skills.
The biggest early intervention model for children with Down syndrome is Total communication (Kumin, 2003). Total communication pairs gestures and sign language with speech. It can also involve Augmentative and Alternative Communication (AAC) modalities as well either low or high tech. As children with Down syndrome are delayed in their speaking, sign language and gestures are typically how children with Down syndrome say their first words. As they develop they will gain more expressive language skills, but the time this takes may vary from a few months to many years (Kumin, 2003). Thus it is very important for a Speech-Language Pathologist to be involved in developing a Total communication system for the child. The parent is also very imperative because they need to be able to use this Total communication system as well. Kumin (2003) suggests that parents be the primary models for good communication skills. She also suggests using real objects and real situations to teach language skills is the most successful (Kumin, 2003).
Multidisciplinary Professionals Involved
As Down syndrome impacts a child’s physical and mental abilities from birth, early intervention is key. Thus a multidisciplinary approach is a major factor in the success of the child. The team should consist of the child’s parents, physician, occupational therapist for feeding, fine motor skills, self-care, cutting, writing, and play (Bruni, 2006), physical therapist for gross motor skills as these are delayed in children with Down syndrome (Winders, 2001), and a Speech-Language Pathologist for communication skills including sign language, AAC devices, receptive and expressive skills as well as pragmatics.
Children with Down syndrome face many physical, mental and communication challenges in their lifetime, but with the right early interventions and support they can lead a fulfilling and normal life. For more information about Down syndrome or to participate in their charity, The Buddy Walk please visit: http://www.ndss.org/
Bruni, M. Bethesda, MD. (2006). Fine Motor Skills for Children withDown Syndrome: A Guide for Parents and Professionals (Second Edition) Woodbine House.. – See more at: http://www.ndss.org/Resources/Therapies-Development/Occupational-Therapy-Down-Syndrome/#sthash.U28sLE1n.dpuf
Buckley S.J. (2000). Speech, language and communication for individuals with Down syndrome-An overview. Down Syndrome Issues and Information.
Buckley, S., Bird, G., & Sacks, B. (1996-2008). Social development for individuals with Down syndrome- An Overview. Down syndrome Education International http://www.down-syndrome.org/information/social/overview
Kumin, L. Bethesda, MD (2003). Early Communication Skills for Children with Down Syndrome. Woodbine House. (See more at: http://www.ndss.org/Resources/Therapies-Development/Speech-Language-Therapy/Speech-Language-Therapy-for-Infants-Toddlers-Young-Children/#sthash.hakY3Jqp.dpuf
Kumin, L. (1998). Comprehensive Speech and Language Treatment for Infants, Toddlers and Children with Down Syndrome. Down Syndrome: A Promising Future, Together. Wiley-Liss, Inc
National Down syndrome Society, What is Down syndrome? http://www.ndss.org/Down-Syndrome/What-Is-Down-Syndrome/
Nordenson, N. & Odle, T. (2006). Down syndrome. In Gale Encyclopedia of Medicine. (3rd ed., Vol. 1). Retrieved from http://www.gale.cengage.com/gvrl/
Pueschel, S. M. (1990). Clinicial Aspects of Down syndrome from Infancy to Adulthood. American Journal of Medical Genetics, Supplement 7: 52-56.
Richard, G.J. & Reiehert Hoge, D. (1999) The Source for Syndromes. Linguisystems
Winders, Patricia C. (2001).The Goal and Opportunity of Physical Therapy for Children with Down Syndrome. Down Syndrome Quarterly 6(2), 1-4. – See more at: http://www.ndss.org/Resources/Therapies-Development/Physical-Therapy-Down-Syndrome/#sthash.Lh1hfnVf.dpuf
Rachel Nortz completed her undergraduate degree in Speech, Language and Hearing Sciences with an emphasis in Audiology at San Diego State University and graduate degree in Communicative Disorders at San Jose State University. For the past four years Rachel has worked with the preschool and elementary aged population. However she also has experience working in a Traumatic Brain Injury -Cognitive Retraining Program, Skilled Nursing Facility, and after school Sensory Training Approach to Reading and Spelling (Reading S.T.A.R.S).