Aplasia cutis congenita (ACC) is a rare disorder characterized by congenital absence of skin. Frieden classified ACC in 1986 into 9 groups on the basis of location of the lesions and associated congenital anomalies. The scalp is the most commonly involved area with lesser involvement of trunk and extremities. Frieden classified ACC with fetus papyraceus as type 5. This type presents as truncal ACC with symmetrical absence of skin in stellate or butterfly pattern with or without involvement of proximal limbs.]It is the most common congenital cicatricial alopecia, and is a congenital focal absence of epidermis with or without evidence of other layers of the skin.

The exact etiology of ACC is still unclear but intrauterine infection by varicella or herpes virus, drugs such as methimazole, misoprostol, valproate, cocaine, marijuana etc., fetus papyraceus, feto-fetal transfusion, vascular coagulation defects, amniotic membrane adherence, abnormal elastic fiber biomechanical forces and trauma are implicated. It can be associated with Johanson-Blizzard syndrome, Adams-Oliver syndrome, trisomy 13, and Wolf-Hirschhorn syndrome.

It can also seen with exposure to methimazole and carbimazole in utero. This dermatological manifestation has been linked to Peptidase D haploinsufficiency and a deletion in Chromosome 19.

This condition has been linked to mutations in the ribosomal GTPase BMS1 gene.

Children with blue diaper syndrome are put on restricted diets. This is in effort to reduce kidney damage. Restrictions include: calcium, protein, vitamin D, and tryptophan. Calcium is restricted to help prevent kidney damage. Examples of food with high levels of tryptophan include turkey and warm milk.

Antibiotics may be used to control or eliminate particular intestinal bacteria. Nicotinic acid may be used to control intestinal infections.

Genetic counseling can also be beneficial, as well as taking part in clinical trials.

Aphalangy, hemivertebrae and urogenital-intestinal dysgenesis is an extremely rare syndrome, described only in three siblings. It associates hypoplasia or aplasia of phalanges of hands and feet, hemivertebrae and various urogenital and/or intestinal abnormalities. Intrafamilial variability is important as one sister had lethal abnormalities (Potter sequence and pulmonary hypoplasia), while her affected brother was in good health with normal psychomotor development at 6 months of age. Prognosis seems to depend mainly on the severity of visceral malformations. Etiology and inheritance remain unknown.

Hennekam syndrome also known as intestinal lymphagiectasia–lymphedema–mental retardation syndrome, is an autosomal recessive disorder consisting of intestinal lymphangiectasia, facial anomalies, peripheral lymphedema, and mild to moderate levels of growth and intellectual disability.

It is also known as "lymphedema-lymphangiectasia-mental retardation syndrome".

In a subset of patients it is associated with CCBE1 according research published by its namesake, Raoul Hennekam. Other causal mutations were found in the FAT4 gene. Previously, mutations in the FAT4 gene had been only associated with van Maldergem syndrome. The molecular mechanism of the lymphedema phenotype in CCBE1-associated cases was identified as a diminished ability of the mutated CCBE1 to accelerate and focus the activation of the primary lymphangiogenic growth factor VEGF-C.

Mungan syndrome is first described in 2003 by Mungan Z. et al. as an autosomal recessively inherited disorder in a Turkish family. It is characterized by mainly gastrointestinal hypomotilily related to visceral neuromyopathy which cause chronic intestinal pseudo-obstruction (CIIP). CIIP is a rare and severe clinical syndrome characterized by symptoms and signs of intestinal occlusion, in the absence of any mechanical obstruction. Family members of this syndrome had also mega duodenum, Barrett's esophagus, different cardiac abnormalities and some other organ involvement. In 2007 Deglincerti A et al. studied genetic abnormalities in this family members and identified a new syndromic locus on chromosome 8q23-q24.

Berdon syndrome, also called Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIH syndrome), is an autosomal recessive fatal genetic disorder affecting newborns. In a 2011 study of 227 children with the syndrome, "the oldest survivor [was] 24 years old." The Ann Arbor News reported a five year old survivor at the end of 2015.

It is more prevalent in females, 7 females to 3 males, and is characterized by constipation and urinary retention, microcolon, giant bladder (megacystis), intestinal hypoperistalis, hydronephrosis, and dilated small bowel. The pathological findings consist of an abundance of ganglion cells in both dilated and narrow areas of the intestine. It is a familial disturbance of unknown cause.

Walter Berdon "et al." in 1976 first described the condition in five female infants, two of whom were sisters. All had marked dilatation of the bladder and some had hydronephrosis and the external appearance of prune belly. The infants also had microcolon and dilated small intestines.

A famous case of IND is that of Adele Chapman, who had a triple transplant of the small intestine, pancreas and liver, the first of its kind in the UK; therefore the official charity of IND is the Adele Chapman Foundation.

Conservative treatment involves the long term use of laxatives and enemas, and has limited success. Dietary changes in order to control the disease are ineffective and high fiber diets often worsen the symptoms in children. As a last resort, surgical treatment (internal sphincter myectomy or colon resection) is used. In extreme cases, the only effective cure is a complete transplant of the affected parts.

Berdon syndrome is autosomal recessive, which means the defective gene is located on an autosome, and two copies of the gene - one inherited from each parent - are required to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but are usually not affected by the disorder.

Several genes are known to be implicated in this syndrome: these include ACTG2, LMOD1, MYH11 and MYLK.

Blue diaper syndrome is a rare, autosomal recessive metabolic disorder characterized in infants by bluish urine-stained diapers. It is also known as Drummond's syndrome, and hypercalcemia.

It is caused by a defect in tryptophan absorption. Bacterial degradation of unabsorbed tryptophan in the intestine leads to excessive indole production and thus to indicanuria which, on oxidation to indigo blue, causes a peculiar bluish discoloration of the diaper (indoluria). Symptoms typically include digestive disturbances, fever and visual problems. Some may also develop disease due to the incomplete breakdown of tryptophan.

It was characterized in 1964, and is associated with the X linked sex gene.

Since this syndrome is X linked, the chance for a child to receive normal genes from both parents and be genetically normal for that particular trait is 25%. If an individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. Carrier females usually do not display symptoms of the disorder because it is usually the X chromosome with the abnormal gene that is “turned off”. Parents can undergo genetic testing to see if their child will get this syndrome, but most do not find out until they see the symptoms mentioned below.

Microvillus inclusion disease is thought to be extremely rare; only approximately 200 cases have been identified in children in Europe.

One patient, a teenage female living in Arizona, suddenly began to grow microvilli after thirteen years of TPN (Total Parenteral Nutrition) and Lipid dependency. She now enjoys a typical teenage diet and is seen regularly by her Gastroenterologist.

One patient from the UK was documented to achieve nutritional independence at age 3.

On 26 June 2009 a six-year-old girl diagnosed with microvillus inclusion disease became the third person in the UK to die of swine flu.

It is nearly always fatal unless, like short bowel syndrome patients, treated with parenteral nutrition or an intestinal transplant. The patient is often classified as being in "intestinal failure" and treated with the cohort of patients known as "short bowel syndrome" patients.

Once the main cause of the disease is treated, a diet of low-fat and high-protein aliments, supplemental calcium and certain vitamins has been shown to reduce symptom effects. This diet, however, is not a cure. If the diet is stopped, the symptoms will eventually reappear.

As of June 2014 (the latest update on HFM in GeneReviews) a total of 32 families had been reported with a clinical diagnosis of HFM of which there was genotypic confirmation in 24 families. Since then, another two confirmed cases have been reported and an additional case was reported based on a clinical diagnosis alone. Most cases emerge from consanguineous parents with homozygous mutations. There are three instances of HFM from non-consanguineous parents in which there were heterozygous mutations. HFM cases are worldwide with mostly private mutations. However, a number of families of Puerto Rican ancestry have been reported with a common pathogenic variant at a splice receptor site resulting in the deletion of exon 3 and the absence of transport function. A subsequent population-based study of newborn infants in Puerto Rico identified the presence of the same variant on the island. Most of the pathogenic variants result in a complete loss of the PCFT protein or point mutations that result in the complete loss of function. However, residual function can be detected with some of the point mutants.

There are currently no specific medical treatments for callosal disorders, but individuals with ACC and other callosal disorders may benefit from a range of developmental therapies, educational support, and services. It is important to consult with a variety of medical, health, educational, and social work professionals. Such professionals include neurologists, neuropsychologists, occupational therapists, physical therapists, speech and language pathologists, pediatricians, music therapists, geneticists, Social workers, special educators, early childhood intervention specialists, and caregivers for adults.

Because HFM is a rare disorder, there are no studies that define its optimal treatment. Correction of the systemic folate deficiency, with the normalization of folate blood levels, is easily achieved with high doses of oral folates or much smaller doses of parenteral folate. This will rapidly correct the anemia, immune deficiency and GI signs. The challenge is to achieve adequate treatment of the neurological component of HFM. It is essential that the folate dose is sufficiently high to achieve CSF folate levels as close as possible to the normal range for the age of the child. This requires close monitoring of the CSF folate level. The physiological folate is 5-methyltetrahydrofolate but the oral formulation available is insufficient for treatment of this disorder and a parenteral form is not available. The optimal folate at this time is 5-formyltetrahydrofolate which, after administration, is converted to 5-methyltetrahydrofolate. The racemic mixture of 5-formyltetrahydrofolate (leucovorin) is generally available; the active S-isomer, levoleucovorin, may be obtained as well. Parenteral administration is the optimal treatment if that is possible. Folic acid should not be used for the treatment of HFM. Folic acid is not a physiological folate. It binds tightly to, and may impede, FRα-mediated endocytosis which plays an important role in the transport of folates across the choroid plexus into the CSF (see above). For a further consideration of treatment see GeneReviews.

There are frequent associated congenital anomalies all related to deviations in the development of anatomical asymmetries in early embryonic stages. These conditions considered together are called "polysplenia syndrome".

Associated conditions include heterotaxy syndrome, intestinal malrotation, situs inversus, biliary atresia, and several cardiac malformations. Associated cardiac conditions include dextrocardia, atrial situs ambiguus, ventricular inversion, and VA concordance with left posterior aorta.

Although present, the multiple small spleens are often ineffective; this is termed functional asplenia.

In utero exposure to cocaine and other street drugs can lead to agenesis of corpus callosum.

There are multiple large-field, multi-country research initiatives focusing on strategies to prevent and treat EE.

- The MAL-ED project

- The Alive and Thrive nutrition project

- The Sanitation, Hygiene and Infant Nutrition Efficacy (SHINE) Trial (ClinicalTrials.gov identifier: NCT01824940)

- The WASH Benefits Study

Differentiation of DIOS from constipation is generally performed by unit specializing in the treatment of cystic fibrosis. Adequate hydration and an aggressive regimen of laxatives are essential for treatment and prevention of DIOS. Osmotic laxatives such as polyethylene glycol are preferred. Individuals prone to DIOS tend to be at risk for repeated episodes and often require maintenance therapy with pancreatic enzyme replacement, hydration and laxatives (if the symptoms are also mild).

Oral contrast instillation into the colon/ileum under radiological control has been found to reduce the need for surgical intervention.

Polysplenia or Chaudhrey's disease is a congenital disease manifested by multiple small accessory spleens, rather than a single, full-sized, normal spleen. Polysplenia sometimes occurs alone, but it is often accompanied by other developmental abnormalities. Conditions associated with polysplenia include gastrointestinal abnormalities, such as intestinal malrotation or biliary atresia, as well as cardiac abnormalities, such as dextrocardia.

Waldmann disease, also known as Waldmann's disease and primary intestinal lymphangiectasia, is a rare disease characterized by enlargement of the lymph vessels supplying the lamina propria of the small intestine.

Although its prevalence is unknown, it being classified as a "rare disease" means that less than 200,000 of the population of the United States are affected by this condition and its subtypes.

Dog breeds commonly affected by lymphangiectasia and/or protein-losing enteropathy include the Soft-Coated Wheaten Terrier, Norwegian Lundehund, Basenji, and Yorkshire Terrier.

Prevention focuses on improving sanitation of water and food sources.

Treatment focuses on addressing the central components of intestinal inflammation, bacterial overgrowth and nutritional supplementation.