Nijmegen breakage syndrome (NBS) Overview Nijmegen breakage syndrome (NBS) is a rare autosomal recessive genetic disorder caused by mutations in the NBN gene (located on chromosome 8q21), which encodes a protein called nibrin. This defect impairs the body's ability to repair double-strand breaks in DNA, leading to chromosomal instability, heightened sensitivity to radiation, and cell damage Symptoms • Microcephaly : A small head circumference that is usually present at birth or becomes noticeable within the first few months and progressively slows down relative to body growth. • Distinctive Facial Features: A sloping forehead, prominent midface/nose, receding lower jaw (mandible), large ears, and sparse hair. • Growth and Developmental Delays: Mild growth restriction leading to short stature, alongside normal early intellectual development followed by mild-to-moderate intellectual disability or learning delays. • Recurrent Infections: Frequent and severe respiratory tract infecti...
Congenital Generalized Lipodystrophy Overview Congenital generalized lipodystrophy (CGL), also known as Berardinelli-Seip syndrome, is a rare genetic disorder characterized by the near total loss of body fat (adipose tissue) and extreme muscularity that is often present at birth or soon thereafter. CGL is associated with metabolic complications related to insulin resistance such as an inability to break down (metabolize) glucose intolerance (high blood glucose levels after oral glucose administration), elevated levels of triglycerides (fat) in the blood (hypertriglyceridemia) and diabetes. Diabetes associated with CGL is often very difficult to treat. Additional complications such as those affecting the liver and heart can also occur. The symptoms and severity of CGL can vary greatly from one person to another. There are four different subtypes of CGL each caused by changes (variants) in different genes. All the known types of CGL are inherited in an autosomal recessive pattern. Lipody...