#congenital defect

• Ablepharia — The congenital partial or total absence of eyelids, studied in physical anthropology, comparative zoology, and developmental biology to understand evolutionary genetic mutations and structural anomalies in vertebrates. In paleoanthropological and animal population dynamics studies, this morphological trait is analyzed as an extreme recessive feature that affects adaptability and visual apparatus protection in environments with intense solar exposure.
• Acrania — A highly severe congenital structural defect characterized by the partial or total absence of the cranial vault (calvaria), while the skull base and facial bones are partially developed.
• Agenetic — Relating to agenesis; characterized by the congenital absence of an organ, tissue, or body part, caused by the failure of its development during embryonic life. In a clinical sense, it describes an organism, anatomical segment, or process affected by this severe structural development anomaly.
• Agenesis — The congenital absence of an organ, tissue, or body part, caused by the failure of its development during embryonic life. Unlike aplasia, where the embryonic bud exists but fails to fully mature, in this severe structural anomaly the initial blueprint of the organ is completely missing from the genetic profile.
• Agenesis — A rare congenital malformation characterized by the complete absence, structural underdeveloped state, or congenital lack of an organ, tissue, or body part since the intrauterine development period. The phenomenon is caused by genetic errors or teratogenic factors manifesting during the early phases of organogenesis.
• Anophthalmia — A severe and rare congenital anomaly characterized by the complete absence of one or both eyeballs, caused by the developmental arrest of the optic vesicles during the first weeks of intrauterine life. This structural lack of the eye results in reduced orbital and eyelid volume, frequently associated with genetic mutations or complex malformative syndromes.
• Anoplasty — A reconstructive or plastic surgical intervention performed on the anus, designed to correct congenital malformations (such as imperforate anus), postoperative cicatricial stenoses, chronic recalcitrant fissures, or severe incontinence. The procedure involves structural remodeling of local cutaneous-mucosal tissues and restoring the normal anatomical functionality of the anal sphincter.
• Anoproctia — A rare pathological condition or congenital structural malformation characterized by the absence of a normal anal opening or by the abnormal fusion of the anal canal with the rectum, blocking digestive transit. In clinical terminology, the term is associated with anorectal imperforation and requires immediate surgical correction after birth to restore patency and physiological evacuation of meconium.
• Aplasia — A congenital or acquired anomaly consisting of the cessation of the development of an organ or tissue, even though its embryonic outline existed normally. This structural disorder translates clinically into the total or partial absence of functional cellular elements, a major example being medullary aplasia, which leads to the cessation of blood cell production.
• Apneumia — An extremely rare congenital malformation characterized by the complete, structural, and anatomical absence of one or both lungs, resulting from an early developmental arrest of the respiratory bud during the embryonic stage. This severe anomaly is investigated within fetal pathology and is typically associated with other major systemic defects.