MedGen

A rare disorder related to monochorionic twin pregnancy characterized by complete or partial absence of cardiac development in one twin (''''acardiac twin'''') and blood supply of both circulations by the morphologically normal co-twin (''''pump twin'''') via an arterioarterial anastomosis. In most cases, the acardiac twin has well developed legs and pelvis but no cephalic pole, thoracic organs, and upper extremities. The condition is associated with a high risk of perinatal death of the pump twin due to a combination of high-output cardiac failure and polyhydramnios-related pre-term birth. Hypoxia and intrauterine growth restriction are also seen in the pump twin. [from ORPHANET]

An extragonadal non-seminomatous malignant germ cell tumor that arises from the mediastinum. It is characterized by the presence of small pale cells with small amount of cytoplasm and round to oval nuclei with small nucleoli forming a variety of patterns, including microcystic, macrocystic, pseudopapillary, myxomatous, hepatoid, polyvesicular vitelline, and solid. It manifests with respiratory distress, thoracic pain, fever, and superior vena cava syndrome. [from NCI]

Nicolaides-Baraitser syndrome (NCBRS) is characterized by sparse scalp hair, prominence of the inter-phalangeal joints and distal phalanges due to decreased subcutaneous fat, characteristic coarse facial features, microcephaly, seizures, and developmental delay / intellectual disability. Seizures are of various types and can be difficult to manage. Developmental delay / intellectual disability (ID) is severe in nearly a half, moderate in a third, and mild in the remainder. Nearly a third never develop speech or language skills. [from GeneReviews]

Nijmegen breakage syndrome (NBS) is characterized by progressive microcephaly, early growth deficiency that improves with age, recurrent respiratory infections, an increased risk for malignancy (primarily lymphoma), and premature ovarian failure in females. Developmental milestones are attained at the usual time during the first year; however, borderline delays in development and hyperactivity may be observed in early childhood. Intellectual abilities tend to decline over time. Recurrent pneumonia and bronchitis may result in respiratory failure and early death. Other reported malignancies include solid tumors (e.g., medulloblastoma, glioma, rhabdomyosarcoma). [from GeneReviews]