Lack of Catch-Up Growth with Growth Hormone Treatment in a Child Born Small for Gestational Age Leading to a Diagnosis of Noonan Syndrome with a Pathogenic PTPN11 Variant

Table 1

Initial laboratory values.

Description	Value	Reference range
Genetic
Karyotype	46, XX	—
Thyroid markers
TSH, high sensitivity	2.977 uIU/mL	0.350–5.5 uIU/mL
Thyroglobulin Ab	<15.0 U/mL	0.0–60.0 U/mL
Thyroid peroxidase Abs	<28.0 IU/mL	1.0–60.0 IU/mL
Endocrine
IGF-1 binding protein 3	2.6 mg/L	1.1–5.2 mg/L
IGF-1	69 ng/mL	55–238 ng/mL
Renal
Ultrasound	Normal findings	—
Inflammatory markers
Celiac disease	Negative	—