Growth Disorders

On this page

Growth Assessment Basics - Measuring Up!

  • Normal Growth Phases:
    • Infancy: Rapid, decelerating growth.
    • Childhood: Slow, steady (approx. 5-7 cm/yr).
    • Puberty: Adolescent growth spurt.
  • Growth Velocity: Rate of growth; key for early detection of deviations.
  • Growth Charts:
    • WHO (0-5 yrs), IAP (>5-18 yrs) charts used in India.
    • Plot height, weight, head circumference.
    • Interpretation: Z-scores (SD from mean), percentiles. WHO Weight-for-Age Growth Chart for Boys (0-2 years)
  • Bone Age (BA):
    • Assesses skeletal maturity & predicts adult height potential.
    • Methods: Greulich-Pyle (hand & wrist X-ray atlas), Tanner-Whitehouse (TW3).
    • ⭐ > Bone age is a better indicator of skeletal maturity and growth potential than chronological age.
  • Mid-Parental Height (MPH):
    • Estimates genetic height potential.
    • Boys: $((\text{Father's Ht (cm)} + \text{Mother's Ht (cm)}) / 2) + \textbf{6.5} \text{ cm}$
    • Girls: $((\text{Father's Ht (cm)} + \text{Mother's Ht (cm)}) / 2) - \textbf{6.5} \text{ cm}$
    • Target height range: MPH $\pm \textbf{8.5}$ cm.

Short Stature - Little Big Issues

  • Definition: Height < -2 SD or < 3rd percentile for age & sex.
  • Classification:
    • Normal Variants: Familial Short Stature (FSS), Constitutional Delay of Growth & Puberty (CDGP).

      FeatureFSSCDGP
      Bone Age (BA)Matches Chronological Age (CA)Delayed (BA ≈ Height Age < CA)
      PubertyNormal timingDelayed
      Adult HeightMatches mid-parental height (short)Normal, within genetic potential
      Family HistoryShort statureDelayed puberty/growth spurt
    • Pathological:

      • Proportionate vs. Disproportionate assessment is key.
      • Key Causes:
        • Endocrine: Growth Hormone Deficiency (GHD), Hypothyroidism.
        • Skeletal Dysplasias (Disproportionate): Achondroplasia.
        • Syndromic: Turner Syndrome, Noonan Syndrome.
        • Systemic Illness: Malnutrition, Chronic Kidney Disease (CKD).
        • Intrauterine Growth Retardation (IUGR) / Small for Gestational Age (SGA).

Dwarfism (Skeletal Dysplasia) Characteristics

⭐ In Constitutional Delay of Growth & Puberty (CDGP), bone age is delayed and matches height age, and adult height is normal an_chieved eventually within genetic potential_

GH Axis & Disorders - The Height Controller

  • GH-IGF-1 Axis Physiology: Hypothalamus (GHRH) → Anterior Pituitary (GH) → Liver & Tissues (IGF-1) → Growth.
    • GH-IGF-1 axis diagram
  • Growth Hormone Deficiency (GHD):
    • Causes: Congenital (e.g., genetic, pituitary hypoplasia) or acquired (e.g., CNS tumor, trauma, irradiation).
    • Clinical Features: Neonatal hypoglycemia, micropenis, prolonged jaundice, decreased growth velocity, cherubic facies.
    • Diagnosis:
      • Screening: ↓ IGF-1, ↓ IGFBP-3 levels (age-specific).
      • Confirmatory: GH stimulation tests (📌 Insulin, Arginine, Clonidine, L-DOPA). Peak GH response < 10 ng/mL is diagnostic.
    • Treatment: Recombinant human GH (rhGH).
  • Laron Syndrome (GH Insensitivity):
    • Autosomal recessive; GH receptor defect.
    • Features: Similar to GHD, but with ↑ GH levels and ↓ IGF-1 levels.

⭐ IGF-1 levels are useful for screening GHD, but definitive diagnosis requires GH stimulation tests where peak GH < 10 ng/mL is a key criterion for GHD diagnosis in children after appropriate priming if necessary (e.g. with sex steroids in peripubertal children).

Syndromic & Other Deviations - Unique Growth Paths

  • Turner Syndrome (45,X0): Short stature, ovarian dysgenesis, webbed neck, coarctation of aorta. 📌 CLOWNS: Cardiac, Lymphoedema, Ovarian dysgenesis, Webbed neck, Nipple (wide), Short stature.
  • Noonan Syndrome (PTPN11): Short stature, distinct facies (e.g., hypertelorism, low-set ears), pulmonic stenosis.
  • Achondroplasia (FGFR3): Rhizomelia (proximal limb shortening), trident hand. Achondroplasia features

    ⭐ Achondroplasia: Most common skeletal dysplasia. Autosomal dominant; most cases new FGFR3 mutations.

  • Tall Stature (>+2SD / >97th percentile):
    • Causes: Familial, Marfan Syndrome (FBN1), Sotos Syndrome (NSD1), Klinefelter (47,XXY), precocious puberty, hyperthyroidism.

High‑Yield Points - ⚡ Biggest Takeaways

  • Familial Short Stature (FSS): Bone age = Chronological age; normal growth velocity.
  • Constitutional Delay (CDGP): Bone age < Chronological age; delayed puberty; normal adult height.
  • GH Deficiency: ↓ Growth velocity, delayed bone age; GH stimulation tests for diagnosis.
  • Turner Syndrome (XO): Female short stature, webbed neck; karyotyping confirms.
  • Achondroplasia: Commonest skeletal dysplasia; disproportionate short stature; FGFR3 mutation.
  • Congenital Hypothyroidism: Growth failure, delayed bone age; screen with TSH, free T4.
  • SGA without catch-up: Risk of persistent short stature.

Practice Questions: Growth Disorders

Test your understanding with these related questions

Bone age is advanced in which of the following conditions?

1 of 5

Flashcards: Growth Disorders

1/10

All of the following are _____ tests for developmental surveillance:

TAP TO REVEAL ANSWER

All of the following are _____ tests for developmental surveillance:

screening

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial