Severe distention of the kidney with dilation of the renal pelvis and calices.

Two sided hypoplasia of the kidney.

A form of polydactyly in which the extra digit or digits are localized on the side of the thumb or great toe.

An abnormality of the intestinal rotation and fixation that normally occurs during the development of the gut. This can lead to volvulus, or twisting of the intestine that causes obstruction and necrosis.

A developmental defect resulting in complete obliteration of the duodenal lumen, that is, an abnormal closure of the duodenum.

Jejunal atresia is the most common cause of bowel obstruction in the newborn. In this condition, because of agenesis of the mesentery, the distal small bowel comes straight off the caecum and twists around the marginal artery, suggesting a maypole, a Christmas tree, or an apple peel at operation. Obliteration of the superior mesenteric artery may underlie this malformation.

Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear.

Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation.

The corpus callosum is the largest fiber tract in the central nervous system and the major interhemispheric fiber bundle in the brain. Formation of the corpus callosum begins as early as 6 weeks' gestation, with the first fibers crossing the midline at 11 to 12 weeks' gestation, and completion of the basic shape by age 18 to 20 weeks (Schell-Apacik et al., 2008). Agenesis of the corpus callosum (ACC) is one of the most frequent malformations in brain with a reported incidence ranging between 0.5 and 70 in 10,000 births. ACC is a clinically and genetically heterogeneous condition, which can be observed either as an isolated condition or as a manifestation in the context of a congenital syndrome (see MOLECULAR GENETICS and Dobyns, 1996). Also see mirror movements-1 and/or agenesis of the corpus callosum (MRMV1; 157600). Schell-Apacik et al. (2008) noted that there is confusion in the literature regarding radiologic terminology concerning partial absence of the corpus callosum, where various designations have been used, including hypogenesis, hypoplasia, partial agenesis, or dysgenesis.

Cerebellar hypoplasia is a descriptive term implying a cerebellum with a reduced volume, but a normal shape and is stable over time.

Underdevelopment of the vermis of cerebellum.

Developmental hypoplasia of the mandible.

A disorder of muscle unrelated to impairment of innervation or neuromuscular junction.

Head circumference below 2 standard deviations below the mean for age and gender.

An accessory spleen is a round, iso-echogenic, homogenic and smooth structure and is seen as a normal variant mostly on the medial contour of the spleen, near the hilus or around the lower pole. This has no pathogenic relevance.

Distance between the oral commissures more than 2 SD above the mean. Alternatively, an apparently increased width of the oral aperture (subjective).

Increased breadth of the nasal bridge (and with it, the nasal root).

Anterior positioning of the nasal root in comparison to the usual positioning for age.

Reduced distance from the anterior border of the naris to the subnasale.

Cleft palate is a developmental defect of the palate resulting from a failure of fusion of the palatine processes and manifesting as a separation of the roof of the mouth (soft and hard palate).

Although hypertelorism means an excessive distance between any paired organs (e.g., the nipples), the use of the word has come to be confined to ocular hypertelorism. Hypertelorism occurs as an isolated feature and is also a feature of many syndromes, e.g., Opitz G syndrome (see 300000), Greig cephalopolysyndactyly (175700), and Noonan syndrome (163950) (summary by Cohen et al., 1995).

Microphthalmia is an eye abnormality that arises before birth. In this condition, one or both eyeballs are abnormally small. In some affected individuals, the eyeball may appear to be completely missing; however, even in these cases some remaining eye tissue is generally present. Such severe microphthalmia should be distinguished from another condition called anophthalmia, in which no eyeball forms at all. However, the terms anophthalmia and severe microphthalmia are often used interchangeably. Microphthalmia may or may not result in significant vision loss.\n\nPeople with microphthalmia may also have a condition called coloboma. Colobomas are missing pieces of tissue in structures that form the eye. They may appear as notches or gaps in the colored part of the eye called the iris; the retina, which is the specialized light-sensitive tissue that lines the back of the eye; the blood vessel layer under the retina called the choroid; or in the optic nerves, which carry information from the eyes to the brain. Colobomas may be present in one or both eyes and, depending on their size and location, can affect a person's vision.\n\nPeople with microphthalmia may also have other eye abnormalities, including clouding of the lens of the eye (cataract) and a narrowed opening of the eye (narrowed palpebral fissure). Additionally, affected individuals may have an abnormality called microcornea, in which the clear front covering of the eye (cornea) is small and abnormally curved.\n\nBetween one-third and one-half of affected individuals have microphthalmia as part of a syndrome that affects other organs and tissues in the body. These forms of the condition are described as syndromic. When microphthalmia occurs by itself, it is described as nonsyndromic or isolated.

A cataract is an opacity or clouding that develops in the crystalline lens of the eye or in its capsule.

A coloboma of the iris.

A congenital abnormality of the cornea in which the cornea and the anterior segment of the eye are smaller than normal. The horizontal diameter of the cornea does not reach 10 mm even in adulthood.

Underdevelopment of the optic nerve.

Anterior segment dysgeneses (ASGD or ASMD) are a heterogeneous group of developmental disorders affecting the anterior segment of the eye, including the cornea, iris, lens, trabecular meshwork, and Schlemm canal. The clinical features of ASGD include iris hypoplasia, an enlarged or reduced corneal diameter, corneal vascularization and opacity, posterior embryotoxon, corectopia, polycoria, an abnormal iridocorneal angle, ectopia lentis, and anterior synechiae between the iris and posterior corneal surface (summary by Cheong et al., 2016). Anterior segment dysgenesis is sometimes divided into subtypes including aniridia (see 106210), Axenfeld and Rieger anomalies, iridogoniodysgenesis, Peters anomaly, and posterior embryotoxon (Gould and John, 2002). Patients with ASGD5 have been reported with the Peters anomaly, Axenfeld anomaly, and Rieger anomaly subtypes. Peters anomaly consists of a central corneal leukoma, absence of the posterior corneal stroma and Descemet membrane, and a variable degree of iris and lenticular attachments to the central aspect of the posterior cornea (Peters, 1906). It occurs as an isolated ocular abnormality or in association with other ocular defects. In Axenfeld anomaly, strands of iris tissue attach to the Schwalbe line; in Rieger anomaly, in addition to the attachment of iris tissue to the Schwalbe line, there is clinically evident iris stromal atrophy with hole or pseudo-hole formation and corectopia (summary by Smith and Traboulsi, 2012).

An eye that is more deeply recessed into the plane of the face than is typical.

A congenital anomaly in which a part or the whole of the cornea acquires the characteristics of sclera, resulting in clouding of the cornea.

The presence of an increased number of twists and turns of the retinal blood vessels.