Developmental Delay Flashcards
What is Developmental Delay?
Considerable delay in the physical or mental development of a child compared with their peers
What is Global developmental delay?
Delay in development in all areas
What is Developmental regression?
Loss of an acquired function or failure to progress after a period of relatively normal development
What is Failure to thrive (faltering weight)?
Insufficient weight gain, or inappropriate weight loss
What is early developmental impairment?
- Developmental skills fall ≥ 2 SD below the population mean in ≥ 2 developmental domains.
- Shown in children under 5 years.
- Occurs in approx 1 – 3 % of the population
What are factors of Early Developmental Impairment?
- Gross/fine motor skills
- Speech/language
- Cognition
- Social/personal
- Activities of daily living
Why do we investigate developmental delay?
- Explanation to parents why child is ‘different’
- Prognostic information
- Set realistic goals
- Access to educational support
- Other support for family
- End the ‘diagnostic odyssey’
- Treatment
- Management of secondary disabilities
- Future pregnancies and the wider family
What is involved in the assessment of a child with developmental delay?
- History
- Developmental assessment
- Physical examination
- Differential diagnosis
- Laboratory investigations
- Routine biochemistry
- Specialist metabolic tests
- Genetics
What is involved in the history in the assessment of a child with developmetal delay?
Most important investigation. Keep a broad view and open mind
- Family history (parents, siblings, grandparents)
- Consanguinity
- Illnesses, early death
- Any attending a special school
- Pregnancy and delivery. If child has problems from birth, are they:
- genetic
- in utero insult
- perinatal events?
- Family environment
- Resources accessible to family
What is involved in the physical examination of a child with developmental delay?
- Height, weight, head circumference using percentile charts
- Birth marks
- Dysmorphic features
- Neurological assessment
- Eyes
- Hearing
- Speech
What are features that point to an inherited metabolic disrder causing developmental delay?
- Parental consanguinity
- Family history of unexplained illness, infant death or late miscarriage
- Symptom-free interval
- Slowing down of skill acquisition
- Loss of skills
- Coarse facial features – metabolic disorder
- Organomegally
What are considerations made when planning tests for developmental delays?
- Cost of test
- Diagnostic yield
- Diagnosis of treatable disorders
- Review the evidence for the test
- Protocol based on clinical findings – differs for each child
- Turnaround time
What are features of CGH microarray in laboratory investigations?
- It is the laboratory test with greatest diagnostic yield in investigation of developmental delay
- Done in Median age 4 years
- Cytogenetic technique which identifies copy number variations. It identifies large deletions or duplications of DNA such as changes of 5 – 10 megabases.
- The genomic DNA from two individuals compared
- Analysed sample in sex-matched pairs
What are indications for CGH microaaray?
- Developmental delay
- Neurodisability
- Congenital abnormalities
- Dysmorphism
What are symptoms of Fragile X syndrome?
- Delayed development, mild intellectual disability, speech and language delay
- Increased CGG triplet repeats on FMR1 gene on X chromosome (> 200, normal 5 – 40)
- May be family history - 1 in 4000 M, 1 in 8000 F
- Specific genetic test is CGH Microarray
Which markers are tested for in the routine biochemistry for the assessment of developmental delay?
- Creatine Kinase
- Calcium, phosphate
- Thyroid Function
- Urea, creatinine, electrolytes
- Calcium, phosphate
- FBC
- Uric acid
Duchenne Muscular Dystrophy: Presentation, Biochemical Test, Treatment
- Test: Creatine Kinase elevated in DMD. Included in 1st line investigation of Early Developmental Impairment in boys.
- Presentation: May present with delayed development
- Treatment: Steroid, New drugs or Clinical trials
What can causes low Creatinine?
- Decreased muscle mass (DMD)
- Analytical interferences (jaffe method) from N-Acetyl cysteine, bilirubin, Lipemia. This is from the enzymatic assay
What are features of thyroid function testing in assessing a child with developmental delay?
- Evidence to include in EDI protocol
- Cheap test
- Hypothyroidism is treatable. Presentation may be variable
- Adverse consequences if missed
- Associated with some chromosomal abnormalities
What affects changes in Calcium and phosphate testing?
- Some chromosomal disorders
- Pseudohypoparathyroidism
What are the features of testing FBC in early developmental delay?
Fe deficiency may be associated with Developmental delay and is treatable
What can uric acid screening be used for?
Screen for purine disorders
What are clinical features of GAMT deficiency?
- Intellectual disability
- Speech and language delay
- Behavioural problems
- Epilepsy
How is GAMT deficiency treated?
Aim to restore cerebral creatine and suppress guanidinoacetate. Give:
- Creatine
- Benzoate (removes glycine)
- Ornithine
