Hypoplasia
Encyclopedia
Hypoplasia is underdevelopment or incomplete development of a tissue or organ. Although the term is not always used precisely, it properly refers to an inadequate or below-normal number of cells. Hypoplasia is similar to aplasia
, but less severe. It is technically not the opposite of hyperplasia
(too many cells). Hypoplasia is a congenital condition, while hyperplasia generally refers to excessive cell growth later in life. (Atrophy, the wasting away of already existing cells, is technically the direct opposite of both hyperplasia and hypertrophy.)
The name is derived from the Greek: hypo, meaning low, and plasis, which refers to molding or forming. The adjective form is hypoplastic.
Hypoplasia can be present in any tissue or organ. It is descriptive of many medical conditions such as:
Underdeveloped:
Aplasia
Aplasia is defined in general as "defective development or congenital absence of an organ or tissue." In the field of hematology, the term refers to "incomplete, retarded, or defective development, or cessation of the usual regenerative process."-Examples:*Acquired pure red cell aplasia*Aplasia...
, but less severe. It is technically not the opposite of hyperplasia
Hyperplasia
Hyperplasia means increase in number of cells/proliferation of cells. It may result in the gross enlargement of an organ and the term is sometimes mixed with benign neoplasia/ benign tumor....
(too many cells). Hypoplasia is a congenital condition, while hyperplasia generally refers to excessive cell growth later in life. (Atrophy, the wasting away of already existing cells, is technically the direct opposite of both hyperplasia and hypertrophy.)
The name is derived from the Greek: hypo, meaning low, and plasis, which refers to molding or forming. The adjective form is hypoplastic.
Hypoplasia can be present in any tissue or organ. It is descriptive of many medical conditions such as:
Underdeveloped:
- Breasts during pubertyPubertyPuberty is the process of physical changes by which a child's body matures into an adult body capable of reproduction, as initiated by hormonal signals from the brain to the gonads; the ovaries in a girl, the testes in a boy...
tuberous breast - Testes in Klinefelter's syndromeKlinefelter's syndromeKlinefelter syndrome, 46/47, XXY, or XXY syndrome is a condition in which human males have an extra X chromosome. While females have an XX chromosomal makeup, and males an XY, affected individuals have at least two X chromosomes and at least one Y chromosome...
- Ovaries in Fanconi anemiaFanconi anemiaFanconi anemia is a genetic disease with an incidence of 1 per 350,000 births, with a higher frequency in Ashkenazi Jews and Afrikaners in South Africa.FA is the result of a genetic defect in a cluster of proteins responsible for DNA repair...
, gonadal dysgenesisGonadal dysgenesisGonadal dysgenesis is a term used to describe multiple reproductive system development disorders. They are conditions of genetic origin. It is characterized by a progressive loss of primordial germ cells on the developing gonads of an embryo....
, trisomy X - ThymusThymusThe thymus is a specialized organ of the immune system. The thymus produces and "educates" T-lymphocytes , which are critical cells of the adaptive immune system....
in DiGeorge syndromeDiGeorge syndrome22q11.2 deletion syndrome, which has several presentations including DiGeorge syndrome , DiGeorge anomaly, velo-cardio-facial syndrome, Shprintzen syndrome, conotruncal anomaly face syndrome, Strong syndrome, congenital thymic aplasia, and thymic hypoplasia is a syndrome caused by the deletion of a... - Labia majoraLabia majoraThe labia majora are two prominent longitudinal cutaneous folds that extend downward and backward from the mons pubis to the perineum and form the lateral boundaries of the pudendal cleft, which contains the labia minora, interlabial sulci, clitoral hood, clitoral glans, frenulum clitoridis, the...
in popliteal pterygium syndromePopliteal pterygium syndromePopliteal pterygium syndrome is an inherited condition affecting the face, limbs, and genitalia. The syndrome goes by a number of names including the popliteal web syndrome and, more inclusively, the facio-genito-popliteal syndrome... - CerebellumCerebellumThe cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
caused by mutation in the ReelinReelinReelin is a large secreted extracellular matrix protein that helps regulate processes of neuronal migration and positioning in the developing brain by controlling cell–cell interactions. Besides this important role in early development, reelin continues to work in the adult brain. It modulates the...
gene - ToothToothTeeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...
caused by oral pathology, such as Turner's hypoplasiaTurner's hypoplasiaTurner's hypoplasia is an abnormality found in teeth. Its appearance is variable, though usually is manifested as a portion of missing or diminished enamel on permanent teeth... - Chambers of the heartHeartThe heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
in hypoplastic left heart syndromeHypoplastic left heart syndromeHypoplastic left heart syndrome , is a rare congenital heart defect in which the left ventricle of the heart is severely underdeveloped.-Causes:...
and hypoplastic right heart syndromeHypoplastic right heart syndromeHypoplastic right heart syndrome is a condition where the right atrium and right ventricle are underdeveloped.It is less common than hypoplastic left heart syndrome.In some cases it can be identified prenatally.It can be associated with aortic stenosis.... - Optic nerveOptic nerveThe optic nerve, also called cranial nerve 2, transmits visual information from the retina to the brain. Derived from the embryonic retinal ganglion cell, a diverticulum located in the diencephalon, the optic nerve doesn't regenerate after transection.-Anatomy:The optic nerve is the second of...
in optic nerve hypoplasiaOptic nerve hypoplasiaOptic nerve hypoplasia is a medical condition arising from the underdevelopment of the optic nerve. This condition is the most common congenital optic nerve anomaly. The optic disc appears abnormally small, because not all the optic nerve axons have developed properly... - SacrumSacrumIn vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
in sacral agenesis - Facial muscle in asymmetric crying faciesAsymmetric crying faciesAsymmetric crying facies , also called Cayler cardiofacial syndrome, partial unilateral facial paresis and hypoplasia of depressor angula oris muscle, is a minor congenital anomaly caused by agenesis or hypoplasia of the depressor anguli oris muscle, one of the muscles that control the movements of...
- ThumbThumbThe thumb is the first digit of the hand. When a person is standing in the medical anatomical position , the thumb is the lateral-most digit...
from birthBirthBirth is the act or process of bearing or bringing forth offspring. The offspring is brought forth from the mother. The time of human birth is defined as the time at which the fetus comes out of the mother's womb into the world... - Lungs, often as a result of oligohydramniosOligohydramniosOligohydramnios is a condition in pregnancy characterized by a deficiency of amniotic fluid. It is the opposite of polyhydramnios.-Diagnosis:Diagnosis is made by ultrasound measurement of the amniotic fluid index...
during gestation or the existence of congenital diaphragmatic herniaCongenital diaphragmatic herniaCongenital diaphragmatic hernia is a congenital malformation of the diaphragm. The most common type of CDH is a Bochdalek hernia; other types include Morgagni's hernia, diaphragm eventration and central tendon defects of the diaphragm... - Small bowel in Coeliac diseaseCoeliac diseaseCoeliac disease , is an autoimmune disorder of the small intestine that occurs in genetically predisposed people of all ages from middle infancy onward...
- Fingers and earsEARSEARS may refer to:* Electoral software* Electronic Arts, Redwood Shores campus.* Emirates Amateur Radio Society...
in Harlequin type ichthyosisHarlequin type ichthyosisHarlequin-type ichthyosis , a skin disease, is the most severe form of congenital ichthyosis, characterized by a thickening of the keratin layer in fetal human skin...
See also
- AplasiaAplasiaAplasia is defined in general as "defective development or congenital absence of an organ or tissue." In the field of hematology, the term refers to "incomplete, retarded, or defective development, or cessation of the usual regenerative process."-Examples:*Acquired pure red cell aplasia*Aplasia...
, when an organ (or part of an organ) is entirely missing - AtrophyAtrophyAtrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations , poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, disuse or lack of exercise or disease intrinsic to the tissue itself...
, when an existing part wastes away - DysplasiaDysplasiaDysplasia , is a term used in pathology to refer to an abnormality of development. This generally consists of an expansion of immature cells, with a corresponding decrease in the number and location of mature cells. Dysplasia is often indicative of an early neoplastic process...
, abnormal development of an organ or extremity - NeoplasiaNeoplasiaNeoplasm is an abnormal mass of tissue as a result of neoplasia. Neoplasia is the abnormal proliferation of cells. The growth of neoplastic cells exceeds and is not coordinated with that of the normal tissues around it. The growth persists in the same excessive manner even after cessation of the...
, new, disordered growth of tissue