Neurology Book

http://www.fpnotebook.com/

Down SyndromeAka: Mongolism, Trisomy 21

Advertisement

  1. Epidemiology
    1. One in 670 to 1000 live births
  2. Risk Factors
    1. Advanced Maternal Age over 34
    2. Prior child with Trisomy 21 (1% recurrence risk)
    3. Carriers of a balanced translocation of Chromosome 21
  3. Pathophysiology
    1. Trisomy of Chromosome 21 (Segment 21q22, long arm)
      1. Usually trisomy of entire chromosome (97%)
      2. May also involve partial chromosome as translocation
  4. Signs
    1. Moderate to severe mental retardation
    2. Hypotonicity
    3. Head and Facies
      1. Brachycephaly (100%)
      2. Small anteroposterior cranial dimension
      3. Posterior third Fontanel
      4. Small, low set ears
      5. Persistent epicanthic folds (90%)
      6. Mongoloid slant eyes (90%)
      7. Esotropia (50%)
      8. Brushfield's Spots (Speckled) of iris (50%)
      9. Short flat nose
      10. Macroglossia (75%)
      11. Small chin
    4. Body Habitus
      1. Broad short neck
      2. Protuberant abdomen
    5. Hands
      1. Short fingers
      2. Curved pinky finger
      3. Single Simian crease with loss of palmar crease
    6. Foot
      1. Absence of whorl on ball of foot
        1. Presence of whorl suggests a normal child
    7. Cardiopulmonary
      1. Cardiac murmur (50%)
  5. Labs
    1. Karyotype
      1. 47 chromosomes with trisomy 21
  6. Associated Conditions
    1. Neurologic
      1. Mental Retardation (IQ of 40-45)
      2. Seizure disorder
      3. Alzheimer's Disease clinically evident
        1. Age 30-39: 0 to 10% Prevalence
        2. Age 40-49: 10 to 25% Prevalence
        3. Age 50-59: 28 to 55% Prevalence
        4. Age 60-69: 30 to 75% Prevalence
    2. Mental Illness (30%)
      1. Major Depression (treat with SSRIs)
      2. Obsessive-Compulsive Disorder
      3. Physical abuse or sexual abuse history
      4. Conduct Disorder
      5. Self-Talk (Soliloquy) is normal (esp. when stressed)
    3. Endocrine
      1. Hypogonadism (100% in males)
      2. Congenital Hypothyroidism (10 to 40%)
      3. Hyperthyroidism
      4. Diabetes Mellitus
    4. Orthopedic
      1. Atlantoaxial Instability (14%)
      2. Spinal cord compression
    5. Cardiovascular
      1. Polycythemia
      2. Mitral Valve Prolapse
      3. Congenital Heart Disease (50%)
        1. Endocardial cushion defect
        2. Ventricular Septal Defect
    6. Gastrointestinal
      1. Duodenal atresia
      2. Bowel Obstruction
    7. Otolaryngology
      1. Obstructive Sleep Apnea (50%)
      2. Conductive and Sensorineural Hearing Loss (70%)
      3. Periodontal Disease and Gingivitis
    8. Ophthalmology
      1. Cataracts (13%)
      2. Refractive Error
      3. Keratoconus (15%)
    9. Dermatology
      1. Xerosis
    10. Malignancy
      1. Acute Myelogenous Leukemia
      2. Acute Lymphocytic Leukemia
      3. Testicular Cancer
  7. Labs: Screening
    1. Blood Glucose periodically
    2. Thyroid Stimulating Hormone (TSH) yearly
  8. Management
    1. Disposition Options for Adult Patients
      1. Independent living with supervision
      2. Group Homes
    2. Adults assumed competent to make medical decisions
      1. Address competence early if questionable
      2. Consider guardianship
      3. Evaluate Advanced Directives
      4. Consider power of attorney for finances and health
  9. Prevention
    1. Standard Child and Adult Immunization Schedules
    2. Routine cancer screening as general population
    3. Specific Disease Screening
      1. See Lab Testing above
      2. Auditory screening every 2 years
      3. Ophthalmology exam every 2 years
      4. Dental exam every 6 months
      5. Major Depression
      6. Alzheimer's Disease (over age 35 to 40 years)
      7. Mitral Valve Prolapse and valvular regurgitation
        1. Screening with careful auscultation sufficient
        2. SBE Prophylaxis if valve disease suspected
        3. Echocardiogram for confirmation
      8. Obstructive Sleep Apnea symptoms and signs
      9. Atlantoaxial Instability
        1. Ask family about Atlantoaxial Instability symptoms
        2. Annual Neurologic Exam of upper extremities
    4. Men's Exam
      1. Testicular exam yearly
    5. Women's Exam
      1. Consider modified Pap Smear
        1. Localize cervical os on bimanual exam
        2. Guide cytology brush into cervical os
      2. Consider pelvic ultrasound instead of bimanual exam
      3. Consider Sedation with anesthesiology support
        1. Consider combining with other procedures if sedated
        2. Sedation medications
          1. Midazolam (Versed) PO or IV
          2. Ketamine
  10. Counseling
    1. Good dental hygiene
    2. Diet and Exercise
    3. Obesity
    4. Tobacco Cessation
    5. Alcohol use
    6. Accident prevention
    7. Contraception
    8. Functional Training
      1. Speech Therapy and Language Therapy
      2. Vocational training or job coach
    9. Support group for parent
  11. Prognosis
    1. Life expectancy: Age 50 to 60 years
  12. Resources
    1. Down Syndrome Clinic of Wisconsin
      1. http://www.family.mcw.edu/dscw
    2. Down Syndrome Health Issues by Dr. Leshin
      1. http://www.ds-health.com
    3. Denison Down Syndrome Quarterly
      1. http://www.denison.edu/dsq
    4. National Down Syndrome Congress
      1. http://www.ndsccenter.org/
    5. National Down Syndrome Society
      1. http://www.ndss.org
  13. References
    1. Cohen (1999) Down Syndrome Quarterly 4:1-15
    2. Smith (2001) Am Fam Physician 64(6):1031

Down Syndrome (C0013080)

Definition (MSH)A chromosome disorder associated either with an extra chromosome 21 or an effective trisomy for chromosome 21. Clinical manifestations include hypotonia, short stature, brachycephaly, upslanting palpebral fissures, epicanthus, Brushfield spots on the iris, protruding tongue, small ears, short, broad hands, fifth finger clinodactyly, Simian crease, and moderate to severe MENTAL RETARDATION. Cardiac and gastrointestinal malformations, a marked increase in the incidence of LEUKEMIA, and the early onset of ALZHEIMER DISEASE are also associated with this condition. Pathologic features include the development of NEUROFIBRILLARY TANGLES in neurons and the deposition of AMYLOID BETA-PROTEIN, similar to the pathology of ALZHEIMER DISEASE. (Menkes, Textbook of Child Neurology, 5th ed, p213)
Definition (NCI)A disorder caused by the presence of an extra chromosome 21 and characterized by mental retardation and distinguishing physical features.
Definition (CSP)chromosome disorder associated either with an extra chromosome 21 or an effective trisomy for chromosome 21; clinical manifestations include hypotonia, short stature, brachycephaly, upslanting palpebral fissures, epicanthus, brushfield spots on the iris, protruding tongue, small ears, short, broad hands, fifth finger clinodactyly, simian crease, and moderate to severe mental retardation.
Definition (NCI)A chromosomal dysgenesis syndrome resulting from a triplication or translocation of chromosome 21. Down syndrome occurs in approximately 1:700 live births. Abnormalities are variable from individual to individual and may include mental retardation, retarded growth, flat hypoplastic face with short nose, prominent epicanthic skin folds, small low-set ears with prominent antihelix, fissured and thickened tongue, laxness of joint ligaments, pelvic dysplasia, broad hands and feet, stubby fingers, transverse palmar crease, lenticular opacities and heart disease. Patients with Down syndrome have an estimated 10 to 30-fold increased risk for leukemia; most have symptoms of Alzheimer's disease by age 40. Also known as trisomy 21 syndrome. --2004
ConceptsCongenital Abnormality (T019) , Disease or Syndrome (T047)
ICD9758.0
EnglishChromosome 21 trisomy, Complete trisomy 21 syndrome, Down Syndrome, Down's Syndrome, Down's syndrome - trisomy 21, Downs Syndrome, G Trisomy, Mongolism, MONGOLOIDISM, SYNDROME DOWN'S, T21 - Trisomy 21, Trisomy 21, Trisomy 21 Syndrome
Spanishmongolismo, sindrome de Down, sindrome de trisomia 21 completa, trisomia del par 21
Parent Conceptsneurodevelopmental anomaly (C0679378), Congenital chromosomal disease (C0008626), Mental Retardation (C0025362), Syndrome (C0039082), Multiple congenital anomalies (C0000772), Hereditary Diseases (C0019247), Trisomy (C0041107), Chromosomal Disorders, Nervous System (C1373232), Down Syndrome (C0013080), Anomaly of chromosome pair 21 (C0265483), Trisomy and partial trisomy of autosome (C0432401), Duplicate concept (C1274013)
SourcesAOD, COSTAR, CSP, CST, DXP, ICD9CM, LCH, LNC, MEDLINEPLUS, MSH, MTH, MTHICD9, NCI, NDFRT, OMIM, SCTSPA, SNOMEDCT
Derived from the NIH UMLS (Unified Medical Language System)



Navigation Tree