Children with global developmental delay usually undergo extensive genetic, neurometabolic and imaging studies. It will be important and  time saving if you can initiate some investigations before referring the child to a specialist.

1) Take a detailed  history and perform a detailed physical examination

2) Referral for auditory and ophthalmologic screening

3) Metabolic studies- blood, urine, and CSF samples for metabolic screen
a. urine organic acid screen
b.  serum amino acids
c.  serum lactate and ammonia levels
d. blood gas
e.  thyroid function test
f. CSF lactate and glycine
g. CSF for neurotransmitters

4) Brain imaging- CT/MRI

5) EEG- if history of epileptic syndrome

6) Evaluation for features suggestive of a specific diagnosis
a. Tests for Downs syndrome, fragile X, Rett syndrome, other genetic disorders,
b. Lead screening in children who have identifiable risk factors for excessive environmental lead exposure

7) Referral to the geneticist  in patients with loss or  regression of developmental milestones, history of parental consanguinity, prior unexplained loss of a child, or multiple miscarriages

8) Referral to other members of the team as required-Community paediatrician, Occupational therapist, Physiotherapist, Orthopaedic surgeon, Orthotics, School/ teacher, nurse, Neurologist, General practitioner, social worker, portage