Down SyndromeDown Syndrome

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ObjectivesObjectives

Be familiar with the genetic basis for Be familiar with the genetic basis for Down SyndromeDown Syndrome

Know the common physical stigmata Know the common physical stigmata of Down Syndromeof Down Syndrome

Be comfortable caring for children Be comfortable caring for children with Down Syndrome and what with Down Syndrome and what testing and routine care is testing and routine care is recommendedrecommended

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EtiologyEtiology

Most commonly recognized genetic Most commonly recognized genetic cause of mental retardation: cause of mental retardation: prevalence of 9.2 cases per 10,000 live prevalence of 9.2 cases per 10,000 live birthsbirths

Diagnosed by Karyotype:Diagnosed by Karyotype: 95% - Trisomy 21 95% - Trisomy 21 2% - Mosaicism (mix of diploid and trisomy 2% - Mosaicism (mix of diploid and trisomy

21)21) 3 % - Robertsonian translocation (part or 3 % - Robertsonian translocation (part or

all of extra chromosome 21 fused with all of extra chromosome 21 fused with another chromosome)another chromosome)

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EtiologyEtiology

95 percent of occurrences of trisomy 21 95 percent of occurrences of trisomy 21 result from nondisjunction during result from nondisjunction during meiotic division of the primary oocytemeiotic division of the primary oocyte

Most trisomy 21 pregnancies prove to Most trisomy 21 pregnancies prove to be nonviablebe nonviable

1/4 of fetuses with trisomy 21 survive to 1/4 of fetuses with trisomy 21 survive to termterm

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Etiology – Risk Etiology – Risk AssessmentAssessment

Maternal AgeMaternal Age 1/1,300 for a 25-year-old woman1/1,300 for a 25-year-old woman 1/365 for age 351/365 for age 35 1/30 for age 451/30 for age 45

At age 35, the second-trimester At age 35, the second-trimester prevalence of trisomy 21 (1/270) prevalence of trisomy 21 (1/270) approaches the estimated risk of fetal approaches the estimated risk of fetal loss due to amniocentesis (1/200) – loss due to amniocentesis (1/200) – This became cutoff for screeningThis became cutoff for screening

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Advanced Maternal Age Advanced Maternal Age as Risk Factoras Risk Factor

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Etiology – Risk Etiology – Risk AssessmentAssessment

15-18 Weeks Gestation : triple test 15-18 Weeks Gestation : triple test detects 60% of pregnancies affected by detects 60% of pregnancies affected by trisomy 21trisomy 21 False positive rate about 5%False positive rate about 5% Alpha-fetoprotein (AFP), unconjugated Alpha-fetoprotein (AFP), unconjugated

estriol and human chorionic gonadotropin estriol and human chorionic gonadotropin (hCG) (hCG)

Ultrasound in 1Ultrasound in 1stst trimester – increases trimester – increases sensitivity to close to 80% with no sensitivity to close to 80% with no change in false positive ratechange in false positive rate

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Etiology – Risk Etiology – Risk AssessmentAssessment

Ultrasound in 2Ultrasound in 2ndnd trimester findings possible: trimester findings possible: Intrauterine growth restrictionIntrauterine growth restriction

Mild cerebral ventriculomegalyMild cerebral ventriculomegalyChoroid plexus cystsChoroid plexus cystsIncreased nuchal fold thicknessIncreased nuchal fold thicknessCystic hygromasCystic hygromasEchogenic intracardiac fociEchogenic intracardiac fociCongenital heart defectsCongenital heart defectsIncreased intestinal echogenicityIncreased intestinal echogenicityDuodenal atresia ("double-bubble sign")Duodenal atresia ("double-bubble sign")Renal pelvis dilationRenal pelvis dilationShortened humerus and femurShortened humerus and femurIncreased iliac wing angleIncreased iliac wing angleIncurving (clinodactyly) and hypoplasia of the fifth Incurving (clinodactyly) and hypoplasia of the fifth fingerfingerIncreased space between first and second toesIncreased space between first and second toesTwo-vessel umbilical cord Two-vessel umbilical cord

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Etiology – Risk Etiology – Risk AssessmentAssessment

Diagnostic Diagnostic procedureprocedure

Gestational Gestational age when age when

test is done test is done (weeks)(weeks)

Risk of Risk of fetal loss fetal loss

(%)(%)

Early Early amniocentesamniocentesisis

10 to 1210 to 12 0.5 to 1.50.5 to 1.5

Early Early amniocentesamniocentesisis

12 to 1512 to 15 1.0 to 2.01.0 to 2.0

2nd-2nd-trimester trimester amniocentesamniocentesisis

15 to 2015 to 20 0.5 to 1.00.5 to 1.0

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Clinical FindingsClinical Findings BrachycephalyBrachycephaly

63-98%63-98% Oblique palpebral Oblique palpebral

fissures fissures 70-98%70-98% 1st & 2nd toe gap 1st & 2nd toe gap 44-97%44-97% Loose skin on neck Loose skin on neck 17-94%17-94% Hyperflexibility Hyperflexibility 47- 92%47- 92% Ear abnormalities Ear abnormalities

(low folded, stenotic)(low folded, stenotic)28-91%28-91% Protruding tongue andProtruding tongue and

small, narrow palate small, narrow palate 32-89%32-89% Flat nasal bridge Flat nasal bridge 57-87%57-87% Muscular hypotonia Muscular hypotonia 21-85%21-85% Epicanthal folds Epicanthal folds 28-79%28-79% Brushfield spots (ring Brushfield spots (ring

of iris speckles) of iris speckles) 35-78%35-78%

Short fifth finger Short fifth finger 51-77%51-77% In-curved fifth finger In-curved fifth finger

43-77%43-77% Short broad hands Short broad hands 38-75%38-75% High arched palate High arched palate 59-74%59-74% Single palmar crease Single palmar crease

42-64%42-64% Cardiac defectCardiac defect

(1/2 AV canal defects)(1/2 AV canal defects)40-50%40-50%

Transient myelodysplasiaTransient myelodysplasia of the newbornof the newborn 10%10%

Duodenal atresiaDuodenal atresia 5-8%5-8%

YellowYellow - Highly specific to - Highly specific to Down Down SyndromeSyndrome

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Medical Medical Problems Problems By SystemBy System

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CardiacCardiac ALL newborns with the syndrome should have an ALL newborns with the syndrome should have an

electrocardiogram and a screening electrocardiogram and a screening echocardiogram, even if a murmur is not present. echocardiogram, even if a murmur is not present.

Most common anomalies are:Most common anomalies are: complete atrioventricular canal defects (60 percent)complete atrioventricular canal defects (60 percent) ventricular septal defects (32 percent)ventricular septal defects (32 percent) tetralogy of Fallot (6 percent)tetralogy of Fallot (6 percent) ostium secundum atrial septal defect (1 percent) ostium secundum atrial septal defect (1 percent)

The long-term prognosis is best when an infant The long-term prognosis is best when an infant with a cardiac defect is promptly referred to a with a cardiac defect is promptly referred to a pediatric cardiologist for medical management to pediatric cardiologist for medical management to prevent pulmonary hypertension or to a pediatric prevent pulmonary hypertension or to a pediatric cardiac surgeon for early surgical repair cardiac surgeon for early surgical repair

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GastrointestinalGastrointestinal

Various Various defectsdefects are associated with are associated with Down syndrome: Esophageal atresia, Down syndrome: Esophageal atresia, Tracheoesophageal fistula, Pyloric Tracheoesophageal fistula, Pyloric stenosis, Duodenal atresia, Meckel's stenosis, Duodenal atresia, Meckel's diverticulum, Hirschsprung's disease, diverticulum, Hirschsprung's disease, Imperforate anusImperforate anus

GERDGERD – may require medication– may require medication ConstipationConstipation – usually dietary – usually dietary

management is enough management is enough

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Ear, Nose and Throat Ear, Nose and Throat Problems Problems

Midfacial malformationsMidfacial malformations prevent optimal prevent optimal drainage of eustachian tubes and sinusesdrainage of eustachian tubes and sinuses susceptible to otitis media, sinusitis and susceptible to otitis media, sinusitis and

pharyngitis pharyngitis sequelae can include hearing loss, chronic sequelae can include hearing loss, chronic

infection, pneumonia, sepsis, endocarditis or infection, pneumonia, sepsis, endocarditis or congestive heart failure in infants with congestive heart failure in infants with concomitant heart defects concomitant heart defects

Auditory brainstem responseAuditory brainstem response testing to testing to evaluate for hearing loss should be evaluate for hearing loss should be performed when an infant with Down performed when an infant with Down syndrome by 6 months oldsyndrome by 6 months old

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Orthopedic Problems Orthopedic Problems Associated problemsAssociated problems: Atlanto-occipital instability, : Atlanto-occipital instability,

Atlantoaxial instability, Hyperflexibility, Scoliosis, Late hip Atlantoaxial instability, Hyperflexibility, Scoliosis, Late hip dislocation (after two years of age), Slipped capital femoral dislocation (after two years of age), Slipped capital femoral epiphysis, Patellar subluxation or dislocation, Foot epiphysis, Patellar subluxation or dislocation, Foot deformities deformities

Xrays of the flexed and extended cervical spine were Xrays of the flexed and extended cervical spine were recommended as screening tests in the past for atlantoaxial recommended as screening tests in the past for atlantoaxial instability when children with Down syndrome reach the instability when children with Down syndrome reach the age of two years or before they undergo general anesthesiaage of two years or before they undergo general anesthesia Although screening radiographs are controversial, 13% of children Although screening radiographs are controversial, 13% of children

with Down syndrome have asymptomatic atlantoaxial instability that with Down syndrome have asymptomatic atlantoaxial instability that should be monitored and that precludes their participation in contact should be monitored and that precludes their participation in contact sportssports

ALL children with Down Syndrome should be referred to ALL children with Down Syndrome should be referred to Early Intervention from birth for physical therapy services Early Intervention from birth for physical therapy services

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Endocrine Disorders Endocrine Disorders

Thyroid DiseaseThyroid Disease – thyroid function – thyroid function tests should be done at birth and at tests should be done at birth and at least annually least annually

Gonadal dysfunction and growth Gonadal dysfunction and growth hormone deficiencyhormone deficiency - These - These problems may require hormonal problems may require hormonal therapy therapy

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OphthalmologyOphthalmology

Congenital cataractsCongenital cataracts - occurs more - occurs more frequently in children with Down syndrome frequently in children with Down syndrome than in other childrenthan in other children Red (fundus) reflexes should be checked at birth.Red (fundus) reflexes should be checked at birth.

Consultation with a pediatric ophthalmologist Consultation with a pediatric ophthalmologist during the first year is necessaryduring the first year is necessary Ocular problems that may be correctable: Ocular problems that may be correctable:

Congenital and acquired cataracts, Nystagmus, Congenital and acquired cataracts, Nystagmus, Strabismus, Dacryostenosis, Blepharitis, Strabismus, Dacryostenosis, Blepharitis, Keratoconus, Refractive errors (myopia, Keratoconus, Refractive errors (myopia, astigmatism), Amblyopia, Increased retinal astigmatism), Amblyopia, Increased retinal vasculature, Glaucoma vasculature, Glaucoma

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Other SystemsOther Systems

Transient myeloproliferative disorderTransient myeloproliferative disorder (leukemoid reaction) occurs in 10% (leukemoid reaction) occurs in 10% Learning point: normal infants who exhibit Learning point: normal infants who exhibit

leukemoid reactions within the 1st two months of life leukemoid reactions within the 1st two months of life should be evaluated by karyotype for mosaic Down should be evaluated by karyotype for mosaic Down syndromesyndrome

SeizuresSeizures - 5-10% of Down Syndrome children - 5-10% of Down Syndrome children DentalDental: Delayed eruption, Atypical patterns of : Delayed eruption, Atypical patterns of

eruption, Congenitally missing teeth, Unusually eruption, Congenitally missing teeth, Unusually shaped teeth, Enamel defects, Orthodontic shaped teeth, Enamel defects, Orthodontic problems, Bruxism, Periodontal disease problems, Bruxism, Periodontal disease

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Psychosocial IssuesPsychosocial Issues Initial Counseling:Initial Counseling:

If not sure of the diagnosis when initial testing If not sure of the diagnosis when initial testing done, say so. “We are concerned that your child done, say so. “We are concerned that your child shows some signs of Down Syndrome and with shows some signs of Down Syndrome and with your permission I would like to draw blood and your permission I would like to draw blood and test for this.” You should point out what physical test for this.” You should point out what physical traits you see to help with denial by the parents.traits you see to help with denial by the parents.

Try to have both parents present when you talk to Try to have both parents present when you talk to them - The parents may react with shock, denial, them - The parents may react with shock, denial, anger, grief, fear, acceptance or any combination anger, grief, fear, acceptance or any combination of these emotions. The physician should of these emotions. The physician should acknowledge the parents' feelings and their right acknowledge the parents' feelings and their right to have them to have them

The infant should be referred to by name, so that The infant should be referred to by name, so that his or her worth as a human being can be stressed.his or her worth as a human being can be stressed.

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Psychosocial IssuesPsychosocial Issues

The mother and father may benefit The mother and father may benefit from an opportunity to meet with the from an opportunity to meet with the parents of an older child with Down parents of an older child with Down syndrome. Such a meeting may syndrome. Such a meeting may provide tangible proof that a child provide tangible proof that a child with Down syndrome can thrive and with Down syndrome can thrive and become a vital part of the family become a vital part of the family

Provide web based and written Provide web based and written resourcesresources

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Final NoteFinal Note

Life tables published in 1989 showed Life tables published in 1989 showed that more than 50 percent of infants that more than 50 percent of infants with Down syndrome could be with Down syndrome could be expected to live more than 50 yearsexpected to live more than 50 years

As mortality rates for the operative As mortality rates for the operative repair of congenital heart defects repair of congenital heart defects continue to decrease, survival may continue to decrease, survival may increase considerably increase considerably

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ResourcesResources BooksBooks

• • Libby Kumin. Communication skills in children with Down syndrome: a guide Libby Kumin. Communication skills in children with Down syndrome: a guide for parents. Rockville, Md.: Woodbine House, 1994. for parents. Rockville, Md.: Woodbine House, 1994. • • Siegfried M. Pueschel. A parent's guide to Down syndrome: toward a Siegfried M. Pueschel. A parent's guide to Down syndrome: toward a brighter future. Baltimore: Paul H. Brookes, 1990. brighter future. Baltimore: Paul H. Brookes, 1990. • • Kay Stray-Gundersen, ed. Babies with Down syndrome: a new parents' Kay Stray-Gundersen, ed. Babies with Down syndrome: a new parents' guide. 2d ed. Bethesda, Md.: Woodbine House, 1995. guide. 2d ed. Bethesda, Md.: Woodbine House, 1995.

    World Wide WebWorld Wide Web

• • America Online America Online --Personal Empowerment Network chatroom (keyword: PEN) --Personal Empowerment Network chatroom (keyword: PEN) --Better Health and Medical Network, disabilities forum, support chats, Down --Better Health and Medical Network, disabilities forum, support chats, Down

syndrome syndrome • • Down Syndrome newsgroup: Down Syndrome newsgroup: http://http://www.downsyndrome.comwww.downsyndrome.com (other (other resources linked to this Web page)   resources linked to this Web page)  

OrganizationsOrganizations • • National Down Syndrome Congress: 1-800-232-6372 National Down Syndrome Congress: 1-800-232-6372 • • National Down Syndrome Society: 1-800-221-4602 National Down Syndrome Society: 1-800-221-4602 • • National Parent to Parent Support and Information System: 1-800-651-1151 National Parent to Parent Support and Information System: 1-800-651-1151 • • La Leche League International (breast-feeding information and support): 1-La Leche League International (breast-feeding information and support): 1-800-525-3243 800-525-3243