# Global Developmental Delay > Global developmental delay for NEET-PG Paediatrics: two-domain definition, hearing and vision first, karyotype, TSH, MRI and Indian causes like kernicterus. - Canonical URL: https://prepelephant.com/topics/neet-pg/paediatrics/global-developmental-delay - Exam / course: NEET-PG · Subject: Paediatrics - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Global Developmental Delay", PrepElephant, https://prepelephant.com/topics/neet-pg/paediatrics/global-developmental-delay ## Direct answer When a child under five shows significant delay — performance two standard deviations or more below the mean — in two or more developmental domains (gross and fine motor, speech and language, social-personal, activities of daily living, cognition), the label is global developmental delay; after about five years of age the equivalent construct is intellectual disability. First-tier evaluation is history and examination: perinatal events, regression (a red flag), consanguinity, dysmorphism, skin, spine and tone — plus mandatory hearing and vision assessment, because sensory deprivation imitates delay and is correctable. Targeted testing follows the clues: thyroid function, chromosomal microarray or karyotype, creatine kinase in boys, neuroimaging when the head is micro- or macrocephalic or the examination is focal, and early intervention started from the first visit rather than after the work-up. ## What you must remember - **Definition to quote:** two standard deviations or more below the mean in two or more domains, under five years; a developmental quotient of 50-69 roughly corresponds to mild delay in Indian texts. - **Domain map with milestones to anchor:** motor — head control by three to four months, sitting by six to nine, walking by 12-18; speech — two-word phrases by two years; social — smile by two months, pointing and joint attention by 12-15 months (loss of joint attention flags autism). - **Red flags for urgent escalation:** no social smile by three months, no sitting by nine, no words by 18, hand preference before one year (hemiparesis until disproved), and any regression of acquired skills. - **First-tier tests (everyone):** hearing (otoacoustic emissions or auditory brainstem response) and vision assessment, thyroid-stimulating hormone (congenital hypothyroidism), complete blood count, and a documented examination for dysmorphism, neurocutaneous stigmata and tone abnormality. - **Second-tier, clue-driven:** microarray or karyotype for dysmorphism (Down syndrome is the commonest chromosomal cause), creatine kinase in a boy with motor delay (Duchenne dystrophy — walks late, Gowers sign), metabolic screen for regression, magnetic resonance imaging for abnormal head size, seizures or focal signs. - **Cerebral palsy boundary:** cerebral palsy is primarily a motor disorder with delayed motor milestones, cognition often preserved; when motor delay dominates with tight adductors and scissoring, the pathway is the cerebral palsy one — the two labels overlap but drive different therapy teams. - **Commonest causes in Indian clinics:** perinatal asphyxia, kernicterus from untreated jaundice, meningitis including tuberculosis, congenital hypothyroidism, Down syndrome, malnutrition and deprivation — a largely preventable burden. - **Intervention principle:** multidisciplinary and early — physiotherapy, occupational and speech therapy, special education, parent training, and Rashtriya Bal Swasthya Karyakram linkage with disability certification. ## How to work through it Structure the answer on an eighteen-month-old who does not walk and says no words. First, let the tone and growth exam set the road: macrocephalic and hypotonic suggests storage disease; microcephalic and hypertonic with scissoring suggests cerebral palsy; a well-grown child with no pointing or joint attention suggests autism. Second, verify the sensory gates — hearing before any label, vision including fixing and following. Third, tier the tests: thyroid-stimulating hormone and microarray for all, creatine kinase if a boy climbs up his thighs, magnetic resonance imaging if head size or tone is abnormal. Fourth, start therapy the same visit and counsel realistic goal-setting rather than delivering a prognosis speech. The contrast case: the same picture with regression — words lost, gait lost. Regression reorders everything: neurometabolic work-up (lactate, ammonia, amino and organic acids), Rett syndrome in a girl, and genetic referral — a "delay" work-up applied to a regressing child wastes the window. ## How the exam frames it Two anchors recur in questions: the two-domain, two-standard-deviation definition, and the "hearing first" principle — testing hearing before labelling a speech-delayed child is the most examinable single step in the chapter. The second family is cause-by-vignette: late walking with calf pseudohypertrophy (Duchenne — creatine kinase), post-asphyxia hypertonia (cerebral palsy), jaundice followed by deafness and choreoathetosis (kernicterus), a stagnant large-tongued child (congenital hypothyroidism). The Indian framing stresses preventable burden — institutional delivery, phototherapy, immunisation against meningitis, iodised salt — alongside Rashtriya Bal Swasthya Karyakram screening and disability certification. ## Frequently asked questions ### What defines global developmental delay? Performance two or more standard deviations below the mean in two or more developmental domains in a child under five years; beyond five, the construct becomes intellectual disability. ### Which assessments are mandatory before labelling a child delayed? Hearing (otoacoustic emissions or auditory brainstem response) and vision — sensory deprivation is common, correctable, and indistinguishable from primary delay on history alone. ### Why is regression of milestones a red flag? Loss of acquired skills points to neurometabolic or neurodegenerative disease, Rett syndrome or autism with regression, redirecting the work-up urgently towards metabolic and genetic testing. ### Which screening test for a boy with predominantly motor delay? Serum creatine kinase — markedly elevated in Duchenne muscular dystrophy, where walking is late and the child climbs up his own thighs (Gowers sign). ### Which national programme covers developmental delays in India? The Rashtriya Bal Swasthya Karyakram screens children for the 4 Ds — defects at birth, deficiencies, diseases and developmental delays including disabilities — linking them to early intervention and support services.