Abnormal development/developmental delay

• Down syndrome: Characterized by hypotonia, distinctive facial features, intellectual disability.
• Fragile X syndrome: Common in boys, features include macroorchidism, hyperactivity, and autistic behavior.
• Rett syndrome: Mostly in girls, presents with normal early development followed by loss of skills, particularly hand use.
• Turner syndrome: Short stature, webbed neck, and learning difficulties, usually in girls.

• Cerebral palsy: Often linked to prematurity or birth complications, presents with spasticity, dyskinesia, or ataxia.
• Epileptic encephalopathies: Seizures with developmental regression, such as in West syndrome.
• Neurocutaneous syndromes: E.g., Tuberous sclerosis, characterized by seizures, intellectual disability, and skin lesions.

• Phenylketonuria (PKU): Untreated cases lead to severe intellectual disability, eczema, and a musty body odor.
• Mitochondrial disorders: Typically present with multi-system involvement, including developmental delay, muscle weakness, and lactic acidosis.
• Lysosomal storage diseases: E.g., Tay-Sachs disease, presents with neurodegeneration and loss of motor skills.

• Fetal alcohol spectrum disorders: Features include microcephaly, smooth philtrum, and developmental delay.
• Lead poisoning: Cognitive impairment, behavioral problems, and developmental delay.
• Intrauterine infections: E.g., congenital CMV or toxoplasmosis, leading to sensorineural hearing loss, microcephaly, and developmental delay.

• Autism spectrum disorder (ASD): Presents with communication difficulties, restricted interests, and repetitive behaviors.
• Attention-deficit/hyperactivity disorder (ADHD): Often presents with inattention, hyperactivity, and impulsivity, potentially affecting developmental milestones.

Assess the achievement of milestones in gross motor, fine motor, speech, language, and social domains. Delays in multiple domains may suggest a global developmental delay, while delays in a single domain may indicate a specific condition (e.g., language delay in hearing impairment).

Parental concerns regarding development are highly predictive of genuine delay. It’s crucial to explore the onset, progression, and context of these concerns.

• Family history: Consider any history of genetic conditions, developmental delay, or learning difficulties in the family.
• Antenatal and perinatal history: Intrauterine exposure to infections, toxins, or complications during birth (e.g., hypoxia) can be significant.
• Social history: Assess the home environment, parental education level, and any potential environmental toxins.
• Drug history: Consider exposure to teratogenic medications or substances during pregnancy.

• Hearing and vision assessment: Essential to rule out sensory impairments.
• Thyroid function tests: Hypothyroidism can present with developmental delay.
• Lead levels: Particularly if there is a history of environmental exposure.

• Karyotyping: To identify chromosomal abnormalities such as Down syndrome.
• FMR1 gene testing: For Fragile X syndrome.
• Microarray analysis: Useful for detecting submicroscopic chromosomal imbalances.

• MRI brain: Indicated if there is evidence of neurodegenerative disease, structural brain anomalies, or in cases of progressive developmental delay.
• EEG: Useful in cases where seizures are suspected or if the child has developmental regression.

• Newborn screening: For conditions like phenylketonuria (PKU) and congenital hypothyroidism.
• Plasma amino acids, urine organic acids: To detect inborn errors of metabolism.
• Lactate and pyruvate levels: To investigate mitochondrial disorders.