Table 1.

Main differential diagnoses for tall stature

Differential diagnosis	Bone age	Centile crossing	HVR	Puberty (N, P or D)	Anatomical features
Transition Age
Familial Tall Stature	↑/ →	< 2 SD	→	N	Normal appearance
FIPA	NA	> 2 SD	NA	N	Tall stature
MAS	↑	NA	↑	P	Café-au-lait spots, skeletal lesions (fibrous osteodysplasia), craniofacial dysplasia (optic and auditory nerve impairment)
Marfan syndrome	NA	> 97th percentile	↑	N	Abnormally long and slender limbs, fingers, toes, chest wall, and scoliosis
Klinefelter syndrome	→	> 2 SD	↑/ → *	N	Small, firm testes; gynecomastia; high-pitched voice; learning disability
Hyperthyroidism	↑	< 2 SD	↑	N	Goiter, tachycardia, hypertension, diarrhea, exophthalmos
Obesity	↑	> 2 SD	↑	P	BMI > 95th percentile
Childhood
Beckwith-Wiedemann syndrome	↑	≥ 2 SD	↓*	NA	Macroglossia, abdominal wall defects, congenital heart disease,
Sotos syndrome	↑	> 2 SD	↑	P#	Macrodolichocephaly, facial alteration
Weaver syndrome	↑	> 98th percentile	NA	NA	Abnormal facial alteration
Simpson–Golabi–Behmel syndrome	↑	> 97th percentile	NA	NA	Macrocephaly, ocular hypertelorism (wide-spaced eyes) with broad upturned nose, macroglossia, and macrostomia (large mouth), supernumerary nipples, pectus excavatum, and hypotonia
Perlman syndrome	NA°	75th–97th percentile	NA°	NA°	Macrosomia, macrocephaly, round facies, hypotonia, visceromegaly, cryptorchidism and inguinal hernia
Tatton–Brown–Rahman syndrome	NA	N/ > 2 SD	NA	P	Macrocephaly noticed at birth, joint hyperlaxity, scoliosis, hypotonia, and seizures

HVR Height Velocity Rate; SD Standard Deviation; N normal onset, P precocious, D Delayed, NA Not Available; FIPA Familial Isolated Pituitary Adenomas; NF1 Neurofibromatosis type 1; MAS McCune-Albright Syndrome; BMI Body Mass Index

^#especially in female patients

^*after 8 years old, before HVR is increased

°due to high mortality rate in the neonatal period