P020ADevelopmental Disabilities
Mrs. Elizabeth Keele, RN
Course Objective #23
• Identify the metabolic problem and the resulting presentation in each of the following recessive inheritance syndromes:– Phenylketonuria– Galactosemia– Tay-Sachs Disease– Hurler Syndrome– Lesch-Nyhan Syndrome– Gaucher’s disease– Neimann-Pick Disease– Wilson’s Disease– Cretinism
Phenylketonuria
• AKA:– PKU
• Gene on chromosome 12– maybe 4 & 11
• Most common inborn error of metabolism
• Incidence– 1:10,000 in USA– carrier 1:50
Phenylketonuria
• Cannot breakdown phenylalanine – h phenylalanine – toxic to CNS
• Screening test – Guthrie test
• Screening timeline– After first 24 hrs. or
before 7-14 days
PhenylketonuriaCommon Features
• Appear – 7-10 days after birth
• ID– if not treated early
• Blond & fair• Musty odor• Microcephaly
PhenylketonuriaCommon Problems
• Vomiting• Irritability• Dry skin / Rash• Seizures
PhenylketonuriaCommon Problems
• “Maternal PKU”
PhenylketonuriaCommon Problems
• If noncompliant with diet – lower IQ– Learning disabilities– behavior problems– Tremors– Eczema– Impaired
communication
PhenylketonuriaCommon Treatment
• TREATABLE!!!!• Low-protein
/phenylalanine diet • Monitor blood
phenylalanine levels• Skin care • Symptom tx
PhenylketonuriaCommon Treatment
• Prevent maternal PKU by – adhering to diet – three months
before/during pregnancy
Galactosemia
• Chromosome 9• Missing liver enzyme– can’t digest milk-
products– Galactose
• Incidence – 1:20,000-1:60,000 live
births
Glactosemia - Pathophysiology
• If an infant with galactosemia is given milk, – Galactose – Toxic levels– Damage
• Liver• Brain• Kidneys• Eyes
GalactosemiaCommon Features
• S&S appear quickly– Vomiting– Jaundice– Lethargy– Irritability– Seizures
• ID is preventable• S&S may be due – E. coli.
GalactosemiaCommon Problems
• Severe ID–Aminoaciduria–Amino acids in
blood • Hepatomegaly– Enlarged liver
• Ascites• Hypoglycemia
If not treated…
• Cataracts• Cirrhosis of the liver• Death • Delayed speech • i ovarian failure• Intellectual disability• E. coli sepsis• Tremors and
uncontrollable motor functions
GalactosemiaCommon Treatment
• Galactose-free diet– life-long
• Calcium supplements
Tay-Sach’s Disease
• Chromosome 15 • Incidence:– 1:30 Jews– 1:270 general population
Tay Sach’s
• Body lacks Hexosamindase A
• h Ganglioside • Nerve and brain cell
destruction • Deathmosis
Tay-Sach’s DiseaseCommon Features
• Appear – about 3-6 months
• Deaf & blind• i muscle tone• Irritable • Paralysis• Seizure
Tay-Sach’s DiseaseCommon Problems
• No cure or treatment• Death by 5 yrs
Tay-Sach’s DiseaseCommon Treatment
• Supportive care• Grief counseling
Hurler’s Syndrome
• AKA:– Gargoylism– Hunter’s
• Cannot breakdown sugar molecule– Glycosaminoglycans
Hurler’s SyndromeCommon Features
–h Muccopolysaccharides /Glycosaminoglycans–Symptoms appear • “Normal” birth• @ 2 yrs
Hurler’s SyndromeCommon Features
• Claw hand• i growth• Heart valve problems• Joint Disease• Thick, coarse facial
features • ID - progressive
Hurler’s SyndromeCommon Problems
• Dwarfism & kyphosis
• Deaf• Corneal clouding• Cardiac • ID
Hurler’s Syndrome-Common Treatment
• Supportive care• Prognosis–Poor
Lesch-Nyhan Syndrome
• AKA – Hyperuricemia– Lip-Biting Syndrome
• X-linked recessive• Incidence – 1:100,000 males
Lesch-Nyhan Syndrome
• Lack enzyme needed to recycle purines
• h uric acid • S&S appear – by 3-6 months
Lesch-Nyhan Syndrome- Common Features
• h uric acid level• Progressive ID• Compulsive, self-
destructive behavior
Lesch-Nyhan SyndromeCommon Problems
• Gout• Kidney stones• Self-mutilation– Lips, mouth, tongue,
fingers
Lesch-Nyhan Syndrome-Common Treatment
• Rx to reduce uric acid– Allopurinol
• Behavior modification• Hydration• Safe environment
Gaucher’s Disease
• Incidence – 1:1,000 Jews
• Chromosome 1• Various types
Gaucher’s Disease-Common Features
• Glucocerebroside (lipid) accumulates in visceral organs
• S&S appear– Different ages
Gaucher’s Disease-Common Features
• Progressive neurological deterioration
• Affects– Liver– Spleen– Lungs– Bone marrow– Brain
Gaucher’s Disease-Common Problems
• Progressive neurological problems
• ID• Bone/joint pain • Type I fatal
Gaucher’s Disease-Common Treatment
• Genetic counseling • Enzyme
replacement therapy
Niemann-Pick Disease
• Gene on chromosome 11
• Incidence – 1:450 Jews– 1:100,000 gen. Pop.
• Can’t metabolize sphingomyelin
Niemann-Pick Disease -Common Features
• h Sphingomyelin • Lipid storage
disease • Cell death &
organ failure
Niemann-Pick Disease -Common Problems
• ID • Progressive motor
skills loss• Enlarged
liver/spleen – jaundice
• S&S r/t –organs affected
Niemann-Pick Disease -Common Treatment
• Supportive & symptomatic• Genetic
counseling
Wilson’s Disease
• Gene on chromosome 13
• Can’t metabolize– copper
• S&S appear –5 -35 yrs
Wilson’s Disease-Common Features
• h Copper• Affects –Liver–CNS–Kayser-Fleischer
rings
Kayser-Fleischer Rings
Wilson’s Disease-Common Treatment
• i Copper diet • water supply
Congenital Hypothyroidism (Cretinism)
• AKA – Congenital
Hypothyroidism
• absence/deficiency of– thyroid hormone
• Early diagnosis critical to prevent ID
• Dx tests: – T3, T4, TSH
Congenital Hypothyroidism (Cretinism)-Common Features
• Dwarfism• Large tongue, • Low metabolic rate• Intolerance to cold
Congenital Hypothyroidism (Cretinism)-Common Problems
• ID• Poor feeding, • Constipation• Short
Congenital Hypothyroidism (Cretinism)-Common Treatment
• Early dx• Replace – Thyroid hormone
Course Objective #24
• Describe features of the following multiple etiology congenital disorders:–Cornelia de Lange Syndrome–Laurence-moon syndrome
Cornelia de Lange Syndrome
• AKA – Brachmann-de Lange
• R/T chromosome 3
Cornelia de Lange Syndrome-Common Features
• Microcephaly• Hirsutism• Low birth weight – failure to thrive
• Short stature• ID – – Severe
• Clinodactyly,• Syndactyly• Cleft palate
Cornelia de Lange Syndrome-Common Problems
• ID• Self-mutilation• Behavior problems• Seizures• Cleft palate• Hearing loss & speech
delay
Cornelia de Lange Syndrome-Common Treatment
• GH• Communication
aides• Special
education• Behavior
modification
Laurence-Moon Syndrome
• Genes on chromosomes– 11, 13, 15, 16
• Incidence – :13,500 Arabs in Kuwait– 1:160,000 gen. pop
Laurence-Moon SyndromeCommon Features
• Gen. obesity • Dwarfism• Skeletal defects• Progressive vision
problems• Hypogenitalism
Laurence-Moon Syndrome-Common Problems
• ID • Blindness• Kidney & cardiac
disorders• Speech problems• Syndactyly• Polydactyly
Laurence-Moon Syndrome-Common Treatment
• Diet• Visual aides• SLP • Kidney care • Surgery – to remove extra
digits
Course Objective #25
• Differentiate between microcephaly and macrocephaly
Microcephaly
• Causes
Microcephaly-Common Features
• Small head
Microcephaly-Common Problems
• ID• Strabismus• Hypertonia• Seizures• Behavior problems
Microcephaly-Common Treatment
• Early intervention• Anticonvulsant
medication
Shunt
Megaloencephaly• 1o – no underlying disease
• 2o – D/T metabolic D/O
• ID– May be normal, MR or
>IQ
Megaloencephaly-Common Features
• h brain weight– > 1600 g
• Normal– 1350-1400 g
• Deformed skull
Megaloencephaly-Common Problems
• ID / DD• Seizures• Neuro deficits
Megaloencephaly-Common Treatment
• Symptomatic treatment
Course Objectives #27
• Explain the difference between cultural-familial retardation and psychosocial disadvantage
Cultural-Familial Retardation
• ID– Mild
• No – Physical disability
• D/T– Environmental causes
• Poor prenatal care• Nutrition• Disease• Toxins
Psychosocial ID
• D/T– psychosocial factors– No organic cause
• Not reversible
• Abuse family• Neglect family
Course #28
• Explain what is meant by a neural tube defect and describe the difference between the various forms of this type of disorder.
Spinal Bifida
Pathophysiology• Congenital Neural Tube
defect• Incomplete closure of the
vertebrae• 3 Levels
– Spina Bifida Occulta– Meningocele– Myelomeningocele
Spina bifida occulta
• Bones of the spine do not close• But the spinal cord and meninges
remain in place• And skin usually covers the defect
Meningocele
• Meninges protrude from the spinal canal• But the spinal cord remains in place
Myelomeningocele
• Both the spinal cord and the meninges protrude from the spinal canal• Co-morbidity–Hydrocephalus
Spinal Bifida• Myelomeningocele must have a
repair of the open neural tube. Failure to repair may result in serious infection which would harm the developing infant brain. After the repair, many children require the insertion of a device called a shunt to divert the cerebral spinal fluid to treat the hydrocephalus.
The Infant with Myelomeningocele
Spinal Bifida
Etiology• Idopathic• Folic acid deficiency
during pregnancy– Esp 1st month
Spinal Bifida
Diagnosis• Ultrasound• h Alpha fetoprotein
Spinal Bifida
• What food contain folic Acid?– Greens– Asparagus– Broccoli– Cauliflower– Corn– Green Beans or Peas– Sweet Potato– Cabbage or Coleslaw
– Black Beans– Lentils– Peas– Peanuts
Course Content #29
• Identify non-genetic biological causes of development disabilities factors that are required–Prenatally–Perinatally–Postnatally
Prenatal
• Toxic substances• Infection
Perinatal
• Premature • Birth injuries– Deprived of O2– Forceps – Nuchal chord
Postnatal
• Brain damage: – Infections• Encephalitis• Meningitis– vaccinations
• mosquitoes • Lead poisoning
– TBI
• Prenatal – Toxic substances (drugs, alcohol)– Infection
• Perinatal– Delivery complications
• Postnatal– Head Injury– Infection