MedGen

Proximal spinal muscular atrophy, i.e., muscular weakness and atrophy related to loss of the motor neurons of the spinal cord and brainstem. [from HPO]

Untreated complete plasminogen activator inhibitor 1 (PAI-1) deficiency is characterized by mild-to-moderate bleeding, although in some instances bleeding can be life threatening. Most commonly, delayed bleeding is associated with injury, trauma, or surgery; spontaneous bleeding does not occur. While males and females with complete PAI-1 deficiency are affected equally, females may present more frequently with clinical manifestations or earlier in life than males due to menorrhagia and postpartum hemorrhage. Fewer than ten families with complete PAI-1 deficiency have been reported to date. The incidence of complete PAI-1 deficiency is higher than expected in the genetic isolate of the Old Order Amish population of eastern and southern Indiana due to a pathogenic founder variant. In one family from this Old Order Amish population, seven individuals had cardiac fibrosis ranging from minimal-to-moderate (6 individuals) to severe (1). [from GeneReviews]

Mandibuloacral dysplasia is a condition that causes a variety of abnormalities involving bone development, skin coloring (pigmentation), and fat distribution. People with this condition may grow slowly after birth. Most affected individuals are born with an underdeveloped lower jaw bone (mandible) and small collar bones (clavicles), leading to the characteristic features of a small chin and sloped shoulders. Other bone problems include loss of bone from the tips of the fingers (acroosteolysis), which causes bulbous finger tips; delayed closure of certain skull bones; and joint deformities (contractures).

MADA usually begins in adulthood, although children can be affected. MADB begins earlier, often just after birth. Many babies with MADB are born prematurely.

People with mandibuloacral dysplasia can have mottled or patchy skin pigmentation or other skin abnormalities. Some people with this condition have features of premature aging (a condition called progeria), such as thin skin, loss of teeth, loss of hair, and a beaked nose. Some individuals with mandibuloacral dysplasia have metabolic problems, such as diabetes.

A common feature of mandibuloacral dysplasia is a lack of fatty tissue under the skin (lipodystrophy) in certain regions of the body. The two types of this disorder, mandibuloacral dysplasia with type A lipodystrophy (MADA) and mandibuloacral dysplasia with type B lipodystrophy (MADB) are distinguished by the pattern of fat distribution throughout the body. Type A is described as partial lipodystrophy; affected individuals have a loss of fatty tissue from the torso and limbs, but it may build up around the neck and shoulders. Type B is a generalized lipodystrophy, with loss of fatty tissue in the face, torso, and limbs. [from MedlinePlus Genetics]

A rare form of metaphyseal dysplasia characterized by short stature, rhizomelic micromelia and a mild varus deformity of the legs evident from the first months of life, that is associated with radiological features of severe metaphyseal changes (irregularities, widening and marginal blurring) in long bones, most prominent in proximal femurs, and generalized osteopenia, and that usually spontaneously resolves by the age of three years. Severe autosomal dominant and milder recessive variants have been observed. [from ORDO]

Spinal muscular atrophy (SMA) is characterized by muscle weakness and atrophy resulting from progressive degeneration and irreversible loss of the anterior horn cells in the spinal cord (i.e., lower motor neurons) and the brain stem nuclei. The onset of weakness ranges from before birth to adulthood. The weakness is symmetric, proximal > distal, and progressive. Before the genetic basis of SMA was understood, it was classified into clinical subtypes based on maximum motor function achieved; however, it is now apparent that the phenotype of SMN1-associated SMA spans a continuum without clear delineation of subtypes. With supportive care only, poor weight gain with growth failure, restrictive lung disease, scoliosis, and joint contractures are common complications; however, newly available targeted treatment options are changing the natural history of this disease. [from GeneReviews]