Dysencephalia splachnocystica or Meckel–Gruber

Dysencephalia splachnocystica, also known as Meckel–Gruber syndrome, is a rare, lethal genetic disorder characterized by a combination of specific features, including cystic dysplasia of the kidneys, occipital encephalocele, and polydactyly. The syndrome is named after the German pathologist Johann Friedrich Meckel and the Swiss pediatrician Georg Gruber.

Etiology

Meckel–Gruber syndrome is an autosomal recessive disorder, which means that both parents must carry a copy of the mutated gene to pass it on to their child. The syndrome is caused by mutations in several different genes, including MKS1, MKS3, and others. These genes are involved in the formation and function of cilia, which are small, hair-like structures that project from the surface of cells and are involved in cell movement and signaling.

Clinical Features

The clinical features of Meckel–Gruber syndrome can vary, but the three main features are occipital encephalocele, cystic dysplasia of the kidneys, and polydactyly.

An occipital encephalocele is a sac-like protrusion or projection of the brain and the membranes that cover it through an opening in the skull. This condition is caused by a defect in the neural tube, a narrow channel that folds and closes during the third and fourth weeks of pregnancy to form the brain and spinal cord of the embryo.

Cystic dysplasia of the kidneys is a condition in which the kidneys are replaced by a large number of cysts (fluid-filled sacs), resulting in a large and spongy appearance. This can lead to kidney failure at an early age.

Polydactyly is a condition in which a person is born with more than the usual number of fingers or toes. In the case of Meckel–Gruber syndrome, the extra digits are usually present on both hands and feet.

Diagnosis and Treatment

Diagnosis of Meckel–Gruber syndrome can be challenging due to its rarity and the variability of its features. It is often diagnosed prenatally through ultrasound examination, which can reveal the characteristic features of the syndrome. Genetic testing can also be used to confirm the diagnosis.

There is currently no cure for Meckel–Gruber syndrome, and treatment is supportive. This can include surgery to repair the encephalocele, dialysis or kidney transplantation for kidney failure, and physical therapy to help with mobility and function.

Prognosis

The prognosis for individuals with Meckel–Gruber syndrome is poor, as most infants with this condition do not survive past the newborn period. However, some individuals with milder forms of the syndrome have been reported to survive into childhood or adolescence.

NIH genetic and rare disease info

• NIH info on Dysencephalia splachnocystica or Meckel–Gruber

Dysencephalia splachnocystica or Meckel–Gruber is a rare disease.