X-linked hypophosphatemia is characterized by low levels of phosphate in the blood (hypophosphatemia), which can lead to skeletal abnormalities. Phosphate is a mineral that is essential for the normal development of bones and teeth. Without adequate READ MORE

X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection, and neoplasia (typically known by the acronym XMEN) is a disorder that affects the immune system in males. In XMEN, certain types of immune system cells called T cells are READ MORE

X-linked infantile nystagmus is a condition characterized by abnormal eye movements. Nystagmus is a term that refers to involuntary side-to-side, up-and-down, or circular movements of the eyes. In people with X-linked infantile nystagmus, the movemen READ MORE

X-linked infantile spinal muscular atrophy is a condition that affects only boys and is characterized by severe muscle weakness and absent reflexes (areflexia). Affected children often have multiple joint deformities (contractures) from birth that ca READ MORE

X-linked intellectual disability, Siderius type is a condition characterized by mild to moderate intellectual disability that affects only males. Affected boys often have delayed development of motor skills such as walking, and their speech may be de READ MORE

X-linked juvenile retinoschisis is a condition characterized by impaired vision that begins in childhood and occurs almost exclusively in males. This disorder affects the retina, which is a specialized light-sensitive tissue that lines the back of th READ MORE

X-linked lissencephaly with abnormal genitalia (XLAG) is a condition that affects the development of the brain and genitalia. It occurs most often in males. XLAG is characterized by abnormal brain development that results in the brain having a smooth READ MORE

X-linked lymphoproliferative disease (XLP) is a disorder of the immune system and blood-forming cells that is found almost exclusively in males. More than half of individuals with this disorder experience an exaggerated immune response to the Epstein READ MORE

X-linked myotubular myopathy is a condition that primarily affects muscles used for movement (skeletal muscles) and occurs almost exclusively in males. People with this condition have muscle weakness (myopathy) and decreased muscle tone (hypotonia) t READ MORE

X-linked severe combined immunodeficiency (SCID) is an inherited disorder of the immune system that occurs almost exclusively in males. Children with X-linked SCID are prone to recurrent and persistent infections because they lack the necessary immun READ MORE

X-linked sideroblastic anemia belongs to a group of disorders that are characterized by a shortage of healthy red blood cells (anemia). X-linked sideroblastic anemia prevents developing red blood cells from making enough hemoglobin, which is the prot READ MORE

X-linked sideroblastic anemia and ataxia is a rare condition that is characterized by a blood disorder called sideroblastic anemia and movement problems known as ataxia. This condition primarily occurs in males. Anemia is defined by a shortage of hea READ MORE