The adducted vocal folds do not close completely but instead remain partially open. The narrow opening between the folds is referred to as the glottis. As air moves through the glottis, it causes a distortion of the air particles which sets the vocal folds into vibratory motion. It is this vibratory motion that produces phonation or voice. In dysphonia, there is an impairment in the ability to produce an appropriate level of phonation. More specifically, it results from an impairment in vocal fold vibration or the nerve supply of the larynx. Diagnosis
The assessment and diagnosis of a dysphonic voice is completed by a multidisciplinary team, such as an otolaryngologist (ear, nose and throat doctor) and Speech-Language Pathologist, involving the use of both objective and subjective measures to evaluate the quality of the voice as well as the condition of the vocal fold tissue and vibration patterns. Definition
Dysphonia is a broad clinical term which refers to abnormal functioning of the voice. More specifically, a voice can be classified as "dysphonic" when there are abnormalities or impairments in one or more of the following parameters of voice: pitch, loudness, quality, and variability. For example, abnormal pitch can be characterized by a voice that is too high or low whereas abnormal loudness can be characterized by a voice that is too quiet or loud. Similarly, a voice that has frequent, inappropriate breaks characterizes abnormal quality while a voice that is monotone (i.e., very flat) or inappropriately fluctuates characterizes abnormal variability.
There are a number of potential treatments that are currently being tested or have just undergone testing including magnesium, etidronate, PPi, and tissue-nonspecific alkaline phosphatase inhibitors.Given that ABCC6 heterozygous mutations result in few symptoms of PXE, this disease is a candidate for gene therapy. Some initial proof-of-principle experiments have been done in mice that have relieved some of symptoms of PXE, but as with all gene therapy treatments, there are many hurdles that must be over come including insuring that the treatment will be long-lasting and reducing the risk of insertional mutagenesis and severe immune reactions. Epidemiology
The reported prevalence of pseudoxanthoma elasticum is about 1:25,000. Females are twice as likely to be affected as males. The disease occurs in all ethnicities, but Afrikaners are more likely to have PXE as a result of a founder effect (i.e., higher prevalence in the small group of people from whom Afrikaners descend). History
The first description of PXE that distinguished it from other xanthoma conditions was by Dr Ferdinand-Jean Darrier in 1896. The eponym "Grönblad-Strandberg syndrome" is used in older literature, after two physicians who made further discoveries in the disease manifestations.PXE has the distinction of being the only disease for which a layperson is the discover of the mutated gene. The ABCC6 gene mutation was discovered simultaneously by four research teams, all of which published at the same time. The principal investigators were (in order of the date of publication): Jouni Uitto, Arthur Bergen, Charles Boyd, and Klaus Lindpainter.