Typically a coloboma appears oval or comet shaped with round end towards the centre. There may be a few vessels (retinal or choroidal) at the edges. The surface may have irregular depression.

Colobomas of the iris may be treated in a number of ways. A simple cosmetic solution is a specialized cosmetic contact lens with an artificial pupil aperture. Surgical repair of the iris defect is also possible. Surgeons can close the defect by stitching in some cases. More recently artificial iris prosthetic devices such as the Human Optics artificial iris have been used successfully by specialist surgeons. This device cannot be used if the natural lens is in place and is not suitable for children. Suture repair is a better option where the lens is still present.

Vision can be improved with glasses, contact lenses or even laser eye surgery but may be limited if the retina is affected or there is amblyopia.

An omphalocele is often detected through AFP screening or a detailed fetal ultrasound. Genetic counseling and genetic testing such as amniocentesis are usually offered during the pregnancy.

Southeast Asian ovalocytosis is a blood disorder that is similar to, but distinct from hereditary elliptocytosis. It is common in some communities in Malaysia and Papua New Guinea, as it confers some resistance to cerebral Falciparum Malaria.

The first noticeable signs of the syndrome usually do not appear until after the first twelve months of the child’s life. The child usually has severe balance issues as he or she learns to sit or walk, often leaning or tilting the head toward the good eye to correct the brain’s skewed perception of the world. Often the child will fall in the same direction while walking or run into objects that are placed on his or her blind side. Additionally, family members may notice a white reflex in the pupil of an affected child instead of the normal red reflex when taking photographs. The presence of this phenomenon is dependent on the degree of the coloboma, with larger colobomas more likely to manifest this particular phenomenon.

This anomaly must be confirmed through pupillary dilation and examination of the optic disc, as the symptoms alone do not constitute a diagnosis.

People with optic nerve colobomas live relatively normal lives. Although non-prescription glasses should be worn for eye protection, this syndrome does not usually prevent the individual from living a normal life, driving cars, playing sports, reading, etc. Certain activities, however, may be more difficult for patients with optic nerve colobomas due to a compromised view of the world. Like most other eye conditions, a diagnosis of optic nerve coloboma precludes a person from certain occupations.

Microcoria is a congenital disease in which the pupils of the subject are narrower than 2 mm in diameter. Microcoria is associated with juvenile-onset glaucoma. It is also associated with Pierson syndrome chararacterized by microcoria and congenital nephrotic syndrome. The defect is in the Laminin beta 2 gene on chromosome 3p21 which encodes a protein essential to the glomerular basement membrane.

It is also part of the known manifestations of a born infant to a mother suffering from uncontrolled hyperglycemia. Other symptoms include transposition of great vessels, respiratory distress secondary to surfactant defect, sacral agensis, jitteriness, irritability, and lethargy due to rebound fetal hypoglycemia. Congenital microcoria is an autosomal dominant trait. However, it can also occur sporadically.

Brunner's findings have been used to argue that genetics, rather than decision-making processes, can cause criminal activity. Evidence supporting the genetic defense stems from both Brunner's findings and a series of studies on mice. To prove the correlation between MAO-A deficiency and aggression in courts, it is often contended that individuals cannot be held accountable for their genes, and as a result, should not be held responsible for their dispositions and resulting actions.

Different features of the dysostosis are significant. Radiological imaging helps confirm the diagnosis. During gestation (pregnancy), clavicular size can be calculated using available nomograms. Wormian bones can sometimes be observed in the skull.

Diagnosis of CCD spectrum disorder is established in an individual with typical clinical and radiographic findings and/or by the identification of a heterozygous pathogenic variant in RUNX2 (CBFA1).

An anopsia or anopia is a defect in the visual field. If the defect is only partial, then the portion of the field with the defect can be used to isolate the underlying cause.

Types of partial anopsia:

- Hemianopsia

- Homonymous hemianopsia

- Heteronymous hemianopsia

- Binasal hemianopsia

- Bitemporal hemianopsia

- Superior hemianopia

- Inferior hemianopia

- Quadrantanopia

The term "anopsia" comes from the Ancient Greek ἀν- ("an-"), "un-" and ὄψις ("opsis") "sight".

Relative afferent pupillary defect (RAPD) or Marcus Gunn pupil is a medical sign observed during the swinging-flashlight test whereupon the patient's pupils constrict less (therefore appearing to dilate) when a bright light is swung from the unaffected eye to the affected eye. The affected eye still senses the light and produces pupillary sphincter constriction to some degree, albeit reduced.

The most common cause of Marcus Gunn pupil is a lesion of the optic nerve (between the retina and the optic chiasm) or severe retinal disease. It is named after Scottish ophthalmologist Robert Marcus Gunn.

A second common cause of Marcus Gunn pupil is a contralateral optic tract lesion, due to the different contributions of the intact nasal and temporal hemifields.

A diagnosis of pentalogy of Cantrell can often be made before birth (prenatally) sometimes using a fetal ultrasound. An ultrasound is an exam that uses high-frequency sound waves to produce an image of the developing fetus. A fetal ultrasound can detect some of the defects associated with pentalogy of Cantrell. An echocardiography is usually performed to evaluate the extent of the involvement of the heart. An echocardiography is an exam that uses sound waves to produce images of the heart

Magnetic resonance imaging (MRI) may also be performed to assess the degree of certain anomalies such as abdominal wall and pericardial defects. An MRI uses a magnetic field and radio waves to produce cross-sectional images of particular organs and bodily tissues.

Coloboma of optic nerve, is a rare defect of the optic nerve that causes moderate to severe visual field defects.

Coloboma of the optic nerve is a congenital anomaly of the optic disc in which there is a defect of the inferior aspect of the optic nerve. The issue stems from incomplete closure of the embryonic fissure while in utero. A varying amount of glial tissue typically fills the defect, manifests as a white mass.

The Marcus Gunn pupil is a relative afferent pupillary defect indicating a decreased pupillary response to light in the affected eye.

In the swinging flashlight test, a light is alternately shone into the left and right eyes. A normal response would be equal constriction of both pupils, regardless of which eye the light is directed at. This indicates an intact direct and consensual pupillary light reflex. When the test is performed in an eye with an afferent pupillary defect, light directed in the affected eye will cause only mild constriction of both pupils (due to decreased response to light from the afferent defect), while light in the unaffected eye will cause a normal constriction of both pupils (due to an intact efferent path, and an intact consensual pupillary reflex). Thus, light shone in the affected eye will produce less pupillary constriction than light shone in the unaffected eye.

A Marcus Gunn pupil is distinguished from a total CN II lesion, in which the affected eye perceives "no" light. In that case, shining the light in the affected eye produces no effect.

Anisocoria is absent. A Marcus Gunn pupil is seen, among other conditions, in optic neuritis. It is also common in retrobulbar optic neuritis due to multiple sclerosis but only for 3–4 weeks, until the visual acuity begins to improve in 1–2 weeks and may return to normal.

Cloacal exstrophy (EC) is a severe birth defect wherein much of the abdominal organs (the bladder and intestines) are exposed. It often causes the splitting of both male and female genitalia (specifically, the penis and clitoris respectively), and the anus is occasionally sealed.

Cloacal exstrophy is a rare birth defect, present in 1/200,000 pregnancies and 1/400,000 live births.

It is caused by a defect of the ventral body wall—mesodermal migration is inhibited and folding fails.

Tracheal agenesis is a rare birth defect with a prevalence of less than 1 in 50,000, in which the trachea fails to develop. The defect is normally fatal, although occasional cases have been reported of long-term survival following surgical intervention.

There are three main types of tracheal agenesis, designated Types I, II and III.

In 2013, a case was reported of a South Korean child with tracheal agenesis who had been successfully treated after having been kept alive in an intensive care unit for the first two and a half years of her life. She then had an artificially created trachea implanted that had been created by tissue engineering using her own stem cells. The patient however later died from complications.

Scott syndrome is a rare congenital bleeding disorder that is due to a defect in a platelet mechanism required for blood coagulation.

Normally when a vascular injury occurs, platelets are activated and phosphatidylserine (PS) in the inner leaflet of the platelet membrane is transported to the outer leaflet of the platelet membrane, where it provides a binding site for plasma protein complexes that are involved in the conversion of prothrombin to thrombin, such as factor VIIIa-IXa (tenase) and factor Va-Xa (prothrombinase).

In Scott syndrome, the mechanism for translocating PS to the platelet membrane is defective, resulting in impaired thrombin formation. A similar defect in PS translocation has also been demonstrated in Scott syndrome red blood cells and Epstein-Barr virus transformed lymphocytes, suggesting that the defect in Scott syndrome reflects a mutation in a stem cell that affects multiple hematological lineages.

The basis for the defect in PS translocation is, at present, unknown. A candidate protein, scramblase, that may be involved in this process appears to be normal in Scott syndrome platelets. Other possible defects in PS translocation, reported in some patients, require further study. The initially reported patient with Scott Syndrome has been found to have a mutation at a splice-acceptor site of the gene encoding transmembrane protein 16F (TMEM16F). At present, the only treatment for episodes of bleeding is the transfusion of normal platelets.

It is hereditary haemolytic anaemia in which the red blood cell is oval-shaped. The primary defect in SAO differs significantly from other forms of elliptocytosis in that it is a defect in the gene coding for a protein that is not directly involved in the cytoskeleton scaffolding of the cell. Rather, the defect lies in a protein known as the band 3 protein, which lies in the cell membrane itself. The band 3 protein normally binds to another membrane-bound protein called ankyrin, but in SAO this bond is stronger than normal. Other abnormalities include tighter tethering of the band 3 protein to the cell membrane, increased tyrosine phosphorylation of the band 3 protein, reduced sulfate anion transport through the cell membrane, and more rapid ATP consumption. These (and probably other) consequences of the SAO mutations lead to the following erythrocyte abnormalities:

- A greater robustness of cells to a variety of external forces, including:

- Reduction in cellular sensitivity to osmotic pressures

- Reduction in fragility related to temperature change

- greater general rigidity of the cell membrane

- Loss of sensitivity to substances that cause of cells

- Reduced anion exchange

- Partial intracellular depletion of ATP

- A reduction in expression of multiple antigens

These changes are thought to give rise to the scientifically and clinically interesting phenomenon that those with SAO exhibit: a marked "in vivo" resistance to infection by the causative pathogen of malaria, "Plasmodium falciparum". Unlike those with the Leach phenotype of common hereditary elliptocytosis (see above), there is a clinically significant reduction in both disease severity and prevalence of malaria in those with SAO. Because of this, the 35% incidence rate of SAO along the north coast of Madang Province in Papua New Guinea, where malaria in endemic, is a good example of natural selection.

The reasons behind the resistance to malaria become clear when given an explanation the way in which "Plasmodium falciparum" invades its host. This parasite is an obligate intracellular parasite, which must enter the cells of the host it is invading. The band 3 proteins aggregate on the cell membrane at the site of entry, forming a circular that the parasite squeezes through. These band 3 proteins act as receptors for the parasite. Normally a process much like endocytosis occurs, and the parasite is able to isolate itself from the intracellular proteins that are toxic to it while still being inside an erythrocyte (see figure 2). The increased rigidity of the erythrocyte membrane in SAO is thought to reduce the capacity of the band 3 proteins to cluster together, thereby making it more difficult for the malaria parasite to properly attaching to and enter the cell. The reduced free ATP within the cell has been postulated as a further mechanism behind which SAO creates a hostile environment for "Plasmodium falciparum".

Imaging by ultrasonography, MRCP, or CT scan usually make the diagnosis. MRCP can be used to define the lesion anatomically prior to surgery.

Occasionally Mirizzi's syndrome is diagnosed or confirmed on ERCP when requested to alleviate obstructive jaundice or cholangitis by means of an endoscopically placed stent, or when USS has been wrongly reported as choledocolithiasis.

Brunner syndrome is a rare genetic disorder associated with a mutation in the MAOA gene. It is characterized by lower than average IQ (typically about 85), problematic impulsive behavior (such as arson, hypersexuality and violence), sleep disorders and mood swings. It was identified in fourteen males from one family in 1993. It has since been discovered in two additional families.

Blau Syndrome is an autosomal dominant genetic inflammatory disorder which affects the skin, eyes, and joints. It is caused by a mutation in the NOD2 (CARD15) gene. Symptoms usually begin before the age of 4, and the disease manifests as early onset cutaneous sarcoidosis, granulomatous arthritis, and uveitis.

Before birth, openings in the abdomen can usually be detected by a detailed ultrasound or AFP screening. In addition to the ultrasound or AFP scanning, it is also necessary for children with this defect to be checked for other birth defects because genetic disorders are usually associated with some of the abdominal wall defects. In looking for other genetic disorders that may be associated, Genetic counseling and further genetic testing, such as amniocentesis, are offered.

Several studies have reported that life expectancy appears to be normal for people with CCD.

The treatment of pentalogy of Cantrell is directed toward the specific symptoms that are apparent in each individual. Surgical intervention for cardiac, diaphragmatic and other associated defects is necessary. Affected infants will require complex medical care and may require surgical intervention. In most cases, pentalogy of Cantrell is fatal without surgical intervention. However, in some cases, the defects are so severe that the individual dies regardless of the medical or surgical interventions received.

The specific treatment strategy will vary from one infant to another based upon various factors, including the size and type of abdominal wall defect, the specific cardiac anomalies that are present, and the particular type of ectopia cordis. Surgical procedures that may be required shortly after birth include repair of an omphalocele. At this time, physicians may also attempt to repair certain other defects including defects of the sternum, diaphragm and the pericardium.

In severe cases, some physicians advocate for a staged repair of the defects associated with pentalogy of Cantrell. The initial operation immediately after birth provides separation of the peritoneal and pericardial cavities, coverage of the midline defect and repair of the omphalocele. After appropriate growth of the thoracic cavity and lungs, the second stage consists of the repair of cardiac defects and return of the heart to the chest. Eventually, usually by age 2 or 3, reconstruction of the lower sternum or epigastrium may be necessary.

Other treatment of pentalogy of Cantrell is symptomatic and supportive.

In 1985 Edward Blau, a pediatrician in Marshfield, Wisconsin, reported a family that over four generations had granulomatous inflammation of the skin, eyes and joints. The condition was transmitted as an autosomal dominant trait. In the same year Jabs et al. reported a family that over two generations had granulomatous synovitis, uveitis and cranial neuropathies. The condition was transmitted in an autosomal dominant fashion. In 1981 Malleson et al. reported a family that had autosomal dominant synovitis, camptodactyly, and iridocyclitis. One member died of granulomatous arteritis of the heart and aorta. In 1982 Rotenstein reported a family with granulomatous arteritis, rash, iritis, and arthritis transmitted as an autosomal dominant trait over three generations. Then in 1990 Pastores et al. reported a kindred with a phenotype very similar to what Blau described and suggested that the condition be called Blau Syndrome (BS). They also pointed out the similarities in the families noted above to BS but also pointed out the significant differences in the phenotypes.

In 1996 Tromp et al. conducted a genome wide search using affected and non affected members of the original family. A marker D16S298gave a maximum LOD score of 3.75 and put the BS susceptibility locus within the 16p12-q21 interval. Hugot et al. found a susceptibility locus for Crohn disease a granulomatous inflammation of the bowel on chromosome 16 close to the locus for BS. Based on the above information Blau suggested in 1998 that the genetic defect in BS and Crohn Disease might be the same or similar.

Finally in 2001 Miceli-Richard et al. found the defect in BS to be in the nucleotide-binding domain of CARD15/NOD2. They commented in their article that mutations in CARD15 had also been found in Crohn's Disease. Confirmation of the defect in BS being in the CARD15 gene was made by Wang et al. in 2002 using the BS family and others. With that information the diagnosis of BS was not only determined by phenotype but now by genotype.

Early onset sarcoidosis is BS without a family history, BS has been diagnosed in patients who have not only the classic triad but granuloma in multiple organs. Treatment has included the usual anti inflammatory drugs such as adrenal glucocorticoids, anti-metabolites and also biological agents such as anti-TNF and infliximab all with varying degrees of success.

The elucidation that the gene defect in BS involves the CARD15/NOD2 gene has stimulated many investigators, to define how this gene operates as part of the innate immune system, that responds to bacterial polysaccharides, such as muramyl dipeptide, to induce signaling pathways that induce cytokine responses, and protect the organism. In BS the genetic defect seems to lead to over expression, and poor control of the inflammatory response leading to widespread granulomatous, inflammation and tissue damage This reference provides an excellent review of the clinical aspects of BS, and the presumed pathogenetic mechanisms brought about by the gene defect.

What stimulus activates the aberrant immune response, and what would then lead to the discovery of more precise therapy, and the relationship to the specific gene defect and phenotype, require further research.

- List of cutaneous conditions

Fetal trimethadione syndrome (also known as paramethadione syndrome, German syndrome, tridione syndrome, among others) is a set of birth defects caused by the administration of the anticonvulsants trimethadione (also known as Tridione) or paramethadione to epileptic mothers during pregnancy.

Fetal trimethadione syndrome is classified as a rare disease by the National Institute of Health's Office of Rare Diseases, meaning it affects less than 200,000 individuals in the United States.

The fetal loss rate while using trimethadione has been reported to be as high as 87%.