"Unexpected" diagnosis.

A young family came from the Siberian region. The first child was born healthy, and the second has a gross developmental delay (by the age of three he does not stand, does not walk, does not sit, gross underdevelopment of speech). Parents associate the appearance of violations with pneumonia transferred at the age of 5 months. At the age of 3, convulsions joined. A diagnosis of epilepsy was made. The diagnosis of cerebral palsy and residual organic lesions of the central nervous system was also made. The external manifestations of the disease clearly did not fit into any genetic syndrome: developmental delay, muscle weakness, increased sweating, irregularly shaped teeth, visual impairment, reduced muscle tone and convulsions.

To exclude a genetic disease, numerous studies were carried out: a karyotype, a panel for neuromuscular diseases and metabolic diseases, a study for spinal amyotrophy, some genetic syndromes - the cause of the disease was not identified. The geneticist recommended whole genome sequencing. Parents turned to the fund for help. The study was conducted and gave unexpected results: the child was found to have a pathogenic point mutation (violation of just one pair of nucleotides), which unambiguously causes a disease called Rett syndrome.

For this syndrome, the child's clinical manifestations are possible, but not very characteristic. That is why research on Rett syndrome has not been conducted.

The data obtained from a genome-wide study will help to supplement the symptom complex of the disease and affect the observation of this child by specialists.