Blue diaper syndrome

Blue diaper syndrome
Other names	Other Names: Hypercalcemia, familial, with nephrocalcinosis and indicanuria
Blue diaper syndrome may have an autosomal recessive pattern of inheritance.
Blue diaper syndrome may have an X-linked recessive pattern of inheritance.
Medication	none

Blue diaper syndrome is a rare, autosomal recessive or X linked recessive metabolic disorder characterized in infants by bluish urine-stained diapers. It is also known as Drummond's syndrome, and hypercalcemia.^[1][2]

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.^[3]

It was characterized in 1964, and inherited in an autosomal recessive pattern although X-linked recessive inheritance has not been completely ruled out since reported patients have been male.^[4]

If 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.^[5] 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".^[3]

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.^[5]

The signs and symptoms of blue diaper syndrome may include irritability, constipation, poor appetite, vomiting, and poor growth. Some children experience frequent fevers and intestinal infections.^[1][3]

Hypercalcemia could be a potential issue in affected children. Some children with blue diaper syndrome have eye or vision issues, particularly underdeveloped portions of the eye, including the cornea and optic disc.^{[citation needed]}

Blue diaper syndrome affects males and females equally. The number of people affected in the general population is unknown.^[1]

Although the disease is most likely recessive, it could be X-linked.^[6]

Recent research indicates that mutations in the LAT2^[7] and TAT1^[8] genes might be involved in causing this syndrome.

It is linked to X linked gene and in order for a person to develop it, both parents must carry the gene.^[3] This syndrome is diagnosed through clinical evaluation and a fresh urine sample ^[3]

A diagnosis is usually made through clinical evaluation, observing detailed patient history then identifying the possible characteristic symptoms and testing fresh urine samples to enhance such evidence.^[1]

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.^[3] Examples of food with high levels of tryptophan include turkey and milk.^[3] Diets are also expected to be low in protein, which will help prevent symptoms, along with restricting vitamin D intake. Antibiotics may be used to control or eliminate particular intestinal bacteria.^{[citation needed]}

Genetic counseling can also be beneficial, as well as taking part in clinical trials.^[9]

• Blue diaper syndrome at NIH's Office of Rare Diseases