evaluation of the child with GDD and intellectual disabilty

Question 1

What is the diagnostic criteria for GDD?

Answer 1

* significant delay (at least 2 SD below mean with standardized tests) in at least 2 developmental domains from following: * gross or fine motor * speech/language * cognition * social/personal * activities of daily living * For children <5 years

Question 2

What is the diagnostic criteria for intellectual disability?

Answer 2

Following criteria must be met:

1. Deficits in intellectual functions: such as reasoning, problem-solving, planning, abstract thinking, judgment, academic learning, learning from experience.
   - Confirmed by both clinical assessment and individualized, standardized intelligence testing.
2. Deficits in adaptive functioning: result in failure to meet developmental and socio-cultural standards for personal independence and social responsibility.
   - Without ongoing support, adaptive deficits limit functioning in one or more activities of daily life, such as communication, social participation, and independent living across multiple environments (home, school, work, and community)
3. onset of intellectual and adaptive deficits during the developmental period levels of severity are not based on IQ, but rather, defined by adaptive functioning

Question 3

In what % of GDD cases is an etiology found?

Answer 3

* Etiology identified in 40-80% of cases * severe ID - identifiable cause in up to 80% of cases * mild ID- identifiable cause in 24%

Question 4

What are the causes of GDD?

Answer 4

Prenatal intrinsic: genetic CNS malformation metabolic Prenatal extrinsic: teratogens/toxins (drugs, meds, etc) infection Perinatal asphyxia prematurity neonatal complications Postnatal neglect/psychosocial environment infections trauma toxins

Question 5

What investigations do you complete for ID/GDD?

Answer 5

Question 6

What test has the best diagnostic yield in GDD/ID?

Answer 6

microarray

Question 7

What is the most common genetic cause for children with ID?

Answer 7

Fragile X

Question 8

When should Rett syndrome testing be done in GDD/ID?

Answer 8

MECP2 molecular analysis when characteristic symptomatology is present (initial N developmdent followed by loss of speech and purposeful hand use, stereotypical hand movement, gait abnormalities) or for moderately-to-severely affected girls

Question 9

What are the indications for lead level testing in GDD/ID?

Answer 9

especially affects < 5 years, leading to ASD, loss of milestones (particularly related to language), encephalopathy