MedGen

The classic phenotype of megalencephalic leukoencephalopathy with subcortical cysts (MLC) is characterized by early-onset macrocephaly, often in combination with mild gross motor developmental delay and seizures; gradual onset of ataxia, spasticity, and sometimes extrapyramidal findings; and usually late onset of mild mental deterioration. Macrocephaly, observed in virtually all individuals, may be present at birth but more frequently develops during the first year of life. The degree of macrocephaly is variable and can be as great as 4 to 6 SD above the mean in some individuals. After the first year of life, head growth rate normalizes and growth follows a line parallel to and usually several centimeters above the 98th centile. Initial mental and motor development is normal in most individuals. Walking is often unstable, followed by ataxia of the trunk and extremities, then minor signs of pyramidal dysfunction and brisk deep-tendon stretch reflexes. Almost all individuals have epilepsy from an early age. The epilepsy is typically well controlled with anti-seizure medication, but status epilepticus occurs relatively frequently. Mental deterioration is late and mild. Disease severity ranges from independent walking for a few years only to independent walking in the fifth decade. Some individuals have died in their teens or twenties; others are alive in their fifties. An improving phenotype has a similar initial presentation with delayed mental or motor development, followed by an improving clinical course: macrocephaly usually persists, but some children become normocephalic; motor function improves or normalizes; hypotonia and clumsiness may persist in some or neurologic examination may become normal. Some have intellectual disability that is stable, with or without autism. Epilepsy and status epilepticus may occur. [from GeneReviews]

The classic phenotype of megalencephalic leukoencephalopathy with subcortical cysts (MLC) is characterized by early-onset macrocephaly, often in combination with mild gross motor developmental delay and seizures; gradual onset of ataxia, spasticity, and sometimes extrapyramidal findings; and usually late onset of mild mental deterioration. Macrocephaly, observed in virtually all individuals, may be present at birth but more frequently develops during the first year of life. The degree of macrocephaly is variable and can be as great as 4 to 6 SD above the mean in some individuals. After the first year of life, head growth rate normalizes and growth follows a line parallel to and usually several centimeters above the 98th centile. Initial mental and motor development is normal in most individuals. Walking is often unstable, followed by ataxia of the trunk and extremities, then minor signs of pyramidal dysfunction and brisk deep-tendon stretch reflexes. Almost all individuals have epilepsy from an early age. The epilepsy is typically well controlled with anti-seizure medication, but status epilepticus occurs relatively frequently. Mental deterioration is late and mild. Disease severity ranges from independent walking for a few years only to independent walking in the fifth decade. Some individuals have died in their teens or twenties; others are alive in their fifties. An improving phenotype has a similar initial presentation with delayed mental or motor development, followed by an improving clinical course: macrocephaly usually persists, but some children become normocephalic; motor function improves or normalizes; hypotonia and clumsiness may persist in some or neurologic examination may become normal. Some have intellectual disability that is stable, with or without autism. Epilepsy and status epilepticus may occur. [from GeneReviews]

The classic phenotype of megalencephalic leukoencephalopathy with subcortical cysts (MLC) is characterized by early-onset macrocephaly, often in combination with mild gross motor developmental delay and seizures; gradual onset of ataxia, spasticity, and sometimes extrapyramidal findings; and usually late onset of mild mental deterioration. Macrocephaly, observed in virtually all individuals, may be present at birth but more frequently develops during the first year of life. The degree of macrocephaly is variable and can be as great as 4 to 6 SD above the mean in some individuals. After the first year of life, head growth rate normalizes and growth follows a line parallel to and usually several centimeters above the 98th centile. Initial mental and motor development is normal in most individuals. Walking is often unstable, followed by ataxia of the trunk and extremities, then minor signs of pyramidal dysfunction and brisk deep-tendon stretch reflexes. Almost all individuals have epilepsy from an early age. The epilepsy is typically well controlled with anti-seizure medication, but status epilepticus occurs relatively frequently. Mental deterioration is late and mild. Disease severity ranges from independent walking for a few years only to independent walking in the fifth decade. Some individuals have died in their teens or twenties; others are alive in their fifties. An improving phenotype has a similar initial presentation with delayed mental or motor development, followed by an improving clinical course: macrocephaly usually persists, but some children become normocephalic; motor function improves or normalizes; hypotonia and clumsiness may persist in some or neurologic examination may become normal. Some have intellectual disability that is stable, with or without autism. Epilepsy and status epilepticus may occur. [from GeneReviews]

Retinitis pigmentosa-10 (RP10) is characterized in most patients by early onset and rapid progression of ocular symptoms, beginning with night blindness in childhood, followed by visual field constriction. Some patients experience an eventual reduction in visual acuity. Funduscopy shows typical changes of RP, including optic disc pallor, retinal vascular attenuation, and bone-spicule pattern of pigmentary deposits in the retinal midperiphery. Electroretinography demonstrates equal reduction in rod and cone responses (Jordan et al., 1993; Bowne et al., 2002; Bowne et al., 2006). For a general phenotypic description and a discussion of genetic heterogeneity of retinitis pigmentosa, see 268000. [from OMIM]

The classic phenotype of megalencephalic leukoencephalopathy with subcortical cysts (MLC) is characterized by early-onset macrocephaly, often in combination with mild gross motor developmental delay and seizures; gradual onset of ataxia, spasticity, and sometimes extrapyramidal findings; and usually late onset of mild mental deterioration. Macrocephaly, observed in virtually all individuals, may be present at birth but more frequently develops during the first year of life. The degree of macrocephaly is variable and can be as great as 4 to 6 SD above the mean in some individuals. After the first year of life, head growth rate normalizes and growth follows a line parallel to and usually several centimeters above the 98th centile. Initial mental and motor development is normal in most individuals. Walking is often unstable, followed by ataxia of the trunk and extremities, then minor signs of pyramidal dysfunction and brisk deep-tendon stretch reflexes. Almost all individuals have epilepsy from an early age. The epilepsy is typically well controlled with anti-seizure medication, but status epilepticus occurs relatively frequently. Mental deterioration is late and mild. Disease severity ranges from independent walking for a few years only to independent walking in the fifth decade. Some individuals have died in their teens or twenties; others are alive in their fifties. An improving phenotype has a similar initial presentation with delayed mental or motor development, followed by an improving clinical course: macrocephaly usually persists, but some children become normocephalic; motor function improves or normalizes; hypotonia and clumsiness may persist in some or neurologic examination may become normal. Some have intellectual disability that is stable, with or without autism. Epilepsy and status epilepticus may occur. [from GeneReviews]

A condition in which the helix is folded over to a greater degree than normal. That is, excessive curling of the helix edge, whereby the free edge is parallel to the plane of the ear. [from HPO]

Absence of the usual parallel position of philtral ridges. [from HPO]

The upper incisors deviate from the normal angle of being roughly parallel to the surface of the face and instead slant outwards. [from HPO]

A well differentiated, low grade neuroendocrine neoplasm (carcinoid tumor) that arises from the small or large intestine. The mitotic count is less than 2 per 10 HPF and/or the Ki67 index is equal to or less than 2 percent. [from NCI]

A deviation from equal (50%) inactivation of each parental X chromosome in maternal cells. [from HPO]

Increased length of the arm span (length from one end of an individual's arms measured at the fingertips to the other when raised parallel to the ground at shoulder height at a one-hundred eighty degree angle). [from HPO]

Normal hemoglobin synthesis is characterized by production of equal amounts of alpha and beta globins. This term refers to a deviation from this pattern and is the main characteristic of the various forms of thalassemia. [from HPO]

If the two laminae of the septum pellucidum are not fused then a fluid-filled space or cavum is present. The cavum septum pellucidum is present at birth but usually obliterates by the age of 3 to 6 months. It is up to 1cm in width and the walls are parallel. It is an enclosed space and is not part of the ventricular system or connected with the subarachnoid space. [from HPO]

A type of acellular urinary cast that are composed only of Tamm-Horsfall glycoprotein, a fact which explains their low refractive index. Hyaline casts may display a spectrum of morphologies, which includes fluffy, compact, convoluted or wrinkled casts. Hyaline casts have a smooth texture and usually have parallel sides with clear margins and blunted ends. [from HPO]

Absence of menses for an interval of time equivalent to a total of more than (or equal to) 3 previous cycles or 6 months. [from HPO]

Astigmatism (from the Greek 'a' meaning absence and 'stigma' meaning point) is a condition in which the parallel rays of light entering the eye through the refractive media are not focused on a single point. Both corneal and noncorneal factors contribute to refractive astigmatism. Corneal astigmatism is mainly the result of an aspheric anterior surface of the cornea, which can be measured readily by means of a keratometer; in a small fraction of cases (approximately 1 in 10) the effect is neutralized by the back surface. The curvature of the back surface of the cornea is not considered in most studies, because it is more difficult to measure; moreover, in the case of severe corneal astigmatism, there is evidence that both surfaces have the same configuration. Noncorneal factors are errors in the curvature of the 2 surfaces of the crystalline lens, irregularity in the refractive index of the lens, and an eccentric lens position. Since the cornea is the dominant component of the eye's refracting system, a highly astigmatic cornea is likely to result in a similarly astigmatic ocular refraction (summary by Clementi et al., 1998). [from OMIM]

Increased volume of dental pulp of permanent molar characterized by a crown body-root ratio equal or larger than 1:1 or an elongated pulp chambers and apical displacement of the bifurcation or trifurcation of the roots. [from HPO]

Thinned, erythematous, depressed bands of atrophic skin. Initially, striae appear as flattened and thinned, pinkish linear regions of the skin. Striae tend to enlarge in length and become reddish or purplish. Later, striae tend to appear as white, depressed bands that are parallel to the lines of skin tension. Striae distensae occur most often in areas that have been subject to distension such as the lower back, buttocks, thighs, breast, abdomen, and shoulders. [from HPO]

Increased size of the heart, clinically defined as an increased transverse diameter of the cardiac silhouette that is greater than or equal to 50% of the transverse diameter of the chest (increased cardiothoracic ratio) on a posterior-anterior projection of a chest radiograph or a computed tomography. [from HPO]

A rare non-syndromic syndactyly characterized by unilateral or bilateral fusion of the 4th and 5th metacarpals with no other associated abnormalities. Patients present shortened 4th and 5th metacarpals with excessive separation between their distal ends, resulting in marked ulnar deviation of the little finger and an inability to bring the 5th finger in parallel with the other fingers. [from ORDO]