Mandibuloacral dysplasia with type B lipodystrophy (MADB) is a rare autosomal recessive disorder characterized by postnatal growth retardation, craniofacial anomalies such as mandibular hypoplasia, skeletal anomalies such as progressive osteolysis of the terminal phalanges and clavicles, and skin changes such as mottled hyperpigmentation and atrophy. The lipodystrophy is characterized by generalized loss of subcutaneous fat involving the face, trunk, and extremities. Some patients have a progeroid appearance. Metabolic complications associated with insulin resistance have been reported (Schrander-Stumpel et al., 1992; summary by Simha et al., 2003). For a general phenotypic description of lipodystrophy associated with mandibuloacral dysplasia, see MADA (248370).

RAPADILINO syndrome is a rare condition that involves many parts of the body. Bone development is especially affected, causing many of the characteristic features of the condition.\n\nMost affected individuals have underdevelopment or absence of the bones in the forearms and the thumbs, which are known as radial ray malformations. The kneecaps (patellae) can also be underdeveloped or absent. Other features include an opening in the roof of the mouth (cleft palate) or a high arched palate; a long, slender nose; and dislocated joints.\n\nMany infants with RAPADILINO syndrome have difficulty feeding and experience diarrhea and vomiting. The combination of impaired bone development and feeding problems leads to slow growth and short stature in affected individuals.\n\nSome individuals with RAPADILINO syndrome have harmless light brown patches of skin that resemble a skin finding known as café-au-lait spots. In addition, people with RAPADILINO syndrome have a slightly increased risk of developing a type of bone cancer known as osteosarcoma or a blood-related cancer called lymphoma. In individuals with RAPADILINO syndrome, osteosarcoma most often develops during childhood or adolescence, and lymphoma typically develops in young adulthood.\n\nThe condition name is an acronym for the characteristic features of the disorder: RA for radial ray malformations, PA for patella and palate abnormalities, DI for diarrhea and dislocated joints, LI for limb abnormalities and little size, and NO for slender nose and normal intelligence.\n\nThe varied signs and symptoms of RAPADILINO syndrome overlap with features of other disorders, namely Baller-Gerold syndrome and Rothmund-Thomson syndrome. These syndromes are also characterized by radial ray defects, skeletal abnormalities, and slow growth. All of these conditions can be caused by mutations in the same gene. Based on these similarities, researchers are investigating whether Baller-Gerold syndrome, Rothmund-Thomson syndrome, and RAPADILINO syndrome are separate disorders or part of a single syndrome with overlapping signs and symptoms.

Mandibuloacral dysplasia with type A lipodystrophy (MADA) is an autosomal recessive disorder characterized by growth retardation, craniofacial anomalies with mandibular hypoplasia, skeletal abnormalities with progressive osteolysis of the distal phalanges and clavicles, and pigmentary skin changes. The lipodystrophy is characterized by a marked acral loss of fatty tissue with normal or increased fatty tissue in the neck and trunk. Some patients may show progeroid features. Metabolic complications can arise due to insulin resistance and diabetes (Young et al., 1971; Simha and Garg, 2002; summary by Garavelli et al., 2009). See also MAD type B (MADB; 608612), which is caused by mutation in the ZMPSTE24 gene (606480).

Inflammatory poikiloderma with hair abnormalities and acral keratoses (IPHAK) is characterized by mottled hyper- and hypopigmentation of the skin as well as sparse scalp hair and eyelashes, sparse or absent eyebrows, and palmoplantar keratoses (Han et al., 2022).