Objectives. Who are Candidates for GH. Growth Charts. Short Stature

Transcription

1 Objectives Short Stature Jackson Smith M.D. Division of Endocrinology University of Kentucky Review growth charts Discuss initial evaluation Mid-parental height Bone age Laboratory studies Identify patients eligible for GH therapy Who are Candidates for GH Growth Charts GH deficient Turner syndrome SGA No catch-up growth by age 2 Idiopathic short stature < 2.25 SD below mean for age Chronic renal failure Pre-transplant Prader-Willi syndrome Noonan syndrome Short stature homeobox (SHOX) gene mutation Clinical growth charts 3 rd to 97 th % tm#set th to 97 th % oth.pdf ocuments/pdf/growth_chart_b oth.pdf OK135S067

2 Definitions Short stature: Height more than 2 SD below the population mean (or less than the 3rd %). Growth failure: Short Stature: Initial Evaluation History Birth length and weight Parent (family) heights and growth history Chronic illnesses and/or medications Nutrition Thorough review of systems Examination Calculate target height Consider obtaining a bone age Height Distribution of Patients General Population Average adult height M: 5' 9 F: 5' 4 Average adult height (US general population*) Height SDS *From Kuczmarski RJ et al NCHS Target Height (Mid-parental Height) Target height for males (inches) = father s height + (mother s height + 5 inches) 2 Target height for females (inches) = mother s height + (father s height - 5 inches) 2 Height may vary by +/- 4 inches (2 SD) from target height

3 AP view of left hand Bone Age Result: age in years (and months) Congruent with age Genetic short stature Primary growth abnormality Delayed = < 2SD for age Nonspecific: Many secondary causes (hypothyroid, GH deficiency) Seen with some primary growth abnormalities Constitutional delay in growth Predicted Height Baley-Pinneau Most commonly used method. May be requested with bone age report: Patients height needed to calculate. If available from radiologist! Assumes a normal growth velocity. Greatest source of inaccuracy: inaccurate bone age interpretation. Short Stature: Differential Diagnosis Conditions evident by age 3. Genetic short stature Constitutional delay of growth Primary growth abnormalities Small for gestational age (SGA) Abnormalities in bone formation: Is the child dysmorphic? Does the child have: Turner syndrome Prader-Willi syndrome Noonan syndrome Secondary Growth Disorders Chronic disease (chronic renal insufficiency) Malnutrition Endocrine Hypothyroidism Growth hormone deficiency Isolated Hypopituitarism Cushing syndrome Calcium and mineralization disorders Rickets Calcium, phosphorus abnormalities M M --- M 6.5 M

4 Genetic Short Stature Other names: familial or intrinsic short stature Height compatible with mid-parental height. Child is: Otherwise healthy Proportional and non-dysmorphic Bone age = chronological age. Follow-up: height maintains same % Constitutional Delay in Growth Diagnosis of exclusion. History and physical exam normal. Family history: delayed growth and/or puberty (not always present). Bone age delayed. Predicted height consistent with parental heights. Growth rate normal. Normal laboratory evaluation: if needed?

5 Laboratory Evaluation Chronic disease and calcium disorders: CBC, sedimentation rate, electolytes, CO2, creatinine, calcium, UA Hypothyroidism: TSH (primary) and Free T4 (central) Growth hormone deficiency: IGF-I Laboratory Evaluation If associated with delayed puberty FSH Others based on history and physical Celiac disease testing Tissue transglutaminase antibody Karyotype Constitutional Delay in Growth Normal growth velocity Typically have a delay in onset of puberty. Abnormal delay: Girls: no breast development by 13 years. Boys: no testicular enlargment by 14 years. Height may drop further below the 3rd % when peers enter puberty. Requires follow-up of linear growth and pubertal development in ~6 months (longer in most cases). SGA 90% will achieve catch-up growth by age 2 (height > 2.3%). 10% will remain < 2SD below average. Adult height SGA patients: height < 3% at age 2 95% will be short adults Pediatric Research 1995;38:733-9 July 2001 FDA approves use of GH for SGA children who do not achieve catch-up growth by 2 years of age. Turner Syndrome Turner Syndrome: Classic Features Incidence: 1:2500 newborn girls Short stature evident by 3 years old (older if mosiac karyotype) Karyotype: Classic: 45,X Many other mosiac forms Dysmorphic features may be few or absent in mosiac varieties Short stature 100% Gonadal failure 94% Abnormal upper-to -lower segment ratio 90% Otitis media 75% Characteristic facies with micrognathia 60% Cubitus valgus 45% Low posterior hairline 40% High arched palate 35% Short metacarpals 35% Genu valgum 30% Multiple nevi 25% Webbed neck 23% Strabismus 17% Scoliosis 12% Nail dysplasia 12%

6 SHOX Mutation Short stature homeobox (SHOX) gene mutation Laboratory Evaluation Chronic disease and calcium disorders: CBC, sedimentation rate, electolytes, CO2, creatinine, calcium, UA Hypothyroidism: TSH (primary) and Free T4 (central) Growth hormone deficiency: IGF-I Laboratory Evaluation If associated with delayed puberty FSH Others based on history and physical Celiac disease testing Tissue transglutaminase antibody Karyotype Idiopathic Short Stature (ISS) Height SDS (1.2 percentile) No distinguishing phenotypic features Likely heterogeneous etiology, such as: Familial/genetic factors Abnormalities of GH/IGF axis Abnormalities of growth plate IGF-I may be normal or low Height velocity may be normal or low GH Treatment of ISS ocuments/pdf/growth_chart_b oth.pdf ISS is a diagnosis of exclusion May include patients with: Genetic short stature Constitutional delay in growth Criteria for possible treatment with GH Predicted adult height (based on BA) Less than 5 feet 3 inches: males Less than 4 feet 11 inches: females GH therapy is not approved to treat less severe short stature!

7 GH Treatment Risks Slipped capital femoral epiphysis Pseudotumor cerebri Pancreatitis Increased long term mortality? Increased death due to bone tumors or cerebral hemorrhage Duration or follow-up from start of GH to time of census or death ~ 17 years Greater risk seen in those on higher dosages J Clin Endocrinol Metab 97: , 2012 GH Treatment Cost About $50 per mg 4 year old (15 kg) = $12,000/year 16 year old (60 kg) = $48,000/year Estimated cost in ISS: $50,000 per inch! (based on 2006 calculation) FDA Approved Indications for GH Therapy GH deficient Turner syndrome Prader-Willi syndrome SGA or IUGR Lack of catch up growth by age 2 Idiopathic short stature < 2.25 SDS or < (1.2 percentile) or Predicted height < 5 3 boys < 4 11 girls Chronic renal failure Pre-transplant