Wilson–Mikity syndrome, a form of chronic lung disease (CLD) that exists only in premature infants, leads to progressive or immediate development of respiratory distress. This rare condition affects low birth babies and is characterized by rapid development of lung emphysema after birth, requiring prolonged ventilation and oxygen supplementation. It is closely related to bronchopulmonary dysplasia (BPD), differing mainly in the lack of prior ventilatory support. All the initial patients described with Wilson–Mikity syndrome were very low birth weight infants that had no history of mechanical ventilation, yet developed a syndrome that clinically resembled BPD. Upon the death of some of these infants, autopsies showed histologic changes similar to those seen in BPD.It was characterized by Miriam G. Wilson and Victor G. Mikity in 1960. Symptoms and signs
The onset of respiratory difficulty occurs at the first day of life and continues up to three weeks into the infants life, at which point treatment is needed for infant survival. Complications
Mothers who have developed chorioamnionitis during pregnancy put their infant at higher risk for development of Wilson-Mikity syndrome. It is a rare complication that requires prolonged treatment. Infection, however, is not shown to be an etiological factor, but a correlation to chorioamnionitis is identified as a risk. Cause
The cause of Wilson-Mikity syndrome is unknown. Diagnosis
The diagnosis of Wilson-Mikity syndrome can be made through two distinct symptoms: analogous characteristics of respiratory distress syndrome and presence of diffuse and streaky infiltrates with small cystic changes, seen through a chest X-ray.
A trisomy is a type of polysomy in which there are three instances of a particular chromosome, instead of the normal two. A trisomy is a type of aneuploidy (an abnormal number of chromosomes). Description and causes
Most organisms that reproduce sexually have pairs of chromosomes in each cell, with one chromosome inherited from each parent. In such organisms, a process called meiosis creates cells called gametes (eggs or sperm) that have only one set of chromosomes. The number of chromosomes is different for different species. Humans have 46 chromosomes (i.e. 23 pairs of chromosomes). Human gametes have only 23 chromosomes. If the chromosome pairs fail to separate properly during cell division, the egg or sperm may end up with a second copy of one of the chromosomes. (See non-disjunction.) If such a gamete results in fertilization and an embryo, the resulting embryo may also have an entire copy of the extra chromosome. Terminology
The number of chromosomes in the cell where trisomy occurs is represented as, for example, 2n+1 if one chromosome shows trisomy, 2n+1+1 if two show trisomy, etc. "Full trisomy", also called "primary trisomy", means that an entire extra chromosome has been copied. "Partial trisomy" means that there is an extra copy of part of a chromosome. "Secondary trisomy" - the extra chromosome has quadruplicated arms (the arms are identical; it is an "isochromosome").