Most of the signs of<unk>  begin to manifest during the first 2–4 years of life. Commons signs at this stage are thickening and scaling of the skin of the palms, soles (palmoplantar keratoderma) and elbows, and shedding of the primary dentition caused by recurrent episodes of dental caries and periodontitis. People also demonstrate thickening and curving of nails (onychogryphosis), flat foot, extreme length and slenderness of fingers and toes (arachnodactyly), and osteolysis involving the distal phalanges of fingers and toes (acro-osteolysis). Permanent flexion contractures of the large and small joints may occur as the disease progresses.
Haim–Munk syndrome
Young–Madders syndrome
Hamman's syndrome
Young's syndrome
Potocki–Lupski syndrome
Ho–Kaufman–Mcalister syndrome
Young–Simpson syndrome
Binder's syndrome