Twenty-nine known mutations in this gene are associated with FHM2 (table 2), many clustering in the large intracellular loop between membrane-spanning segments 4 and 5 (figure 1). Twelve of these mutations have been studied by expression in model cells. All but one have shown either complete loss of function or more complex decreases in ATPase activity or potassium sensitivity. Astrocytes expressing these mutant ion pumps will have much higher resting potentials and are believed to lead to disease through a poorly understood mechanism. FHM3 (SCN1A)
The final known locus FHM3 is the SCN1A gene, which encodes a sodium channel α subunit. The only study so far that has found mutations in this gene discovered the same Q1489K mutation in three of 20 families (15%) with 11 other kindreds (55%) already having mutations in CACNA1A or ATP1A2. This mutation is located in a highly conserved region of an intracellular loop connecting domains three and four. This mutation results in a greatly hastened (two- to four-fold) recovery from inactivation compared to wild-type. As this channel is important for action potential generation in neurons,  the Q1489K mutant is expected to result in hyperexcitable neurons. FHM4 (1q31)
The final locus for FHM maps to the q-arm of chromosome 1. A number of attractive candidate genes occur in this area, though no mutations in them have yet been linked to FHM4.
Julian Nowak later proposed the name mycoplasma for certain filamentous microorganisms imagined to have both cellular and acellular stages in their lifecycles, which could explain how they were visible with a microscope, but passed through filters impermeable to other bacteria. Later, the name for these mycoplasmas was pleuropneumonia-like organisms (PPLO), broadly referring to organisms similar in colonial morphology and filterability to the causative agent (a Mycoplasma species) of contagious bovine pleuropneumonia. At present, all these organisms are classified as Mollicutes and the term Mycoplasma refers solely to the genus. Species that infect humans
Species of Mycoplasma, other than those listed below, have been recovered from humans, but are assumed to have been contracted from a non-human host. The following species use humans as the primary host:

Pathophysiology
Mycoplasma species have been isolated from women with bacterial vaginosis. M. genitalium is found in women with pelvic inflammatory disease. In addition, infection is associated with increased risk of cervicitis, infertility, preterm birth and spontaneous abortion. Mycoplasma genitalium has developed resistance to some antibiotics. Mycoplasma species are associated with infant respiratory distress syndrome, bronchopulmonary dysplasia, and intraventricular hemorrhage in preterm infants. Characteristics
Over 100 species have been included in the genus Mycoplasma, a member of the class Mollicutes. They are parasites or commensals of humans, animals, and plants. The genus Mycoplasma uses vertebrate and arthropod hosts. Dietary nitrogen availability has been shown to alter codon bias and genome evolution in Mycoplasma and Phytoplasma.Mycoplasma species are among the smallest free-living organisms (about 0.2 - 0.3 µm in diameter).