Negative PCR does not rule out VZV involvement, but a positive PCR can be used for diagnosis, and appropriate treatment started (for example, antivirals can be prescribed rather than antibiotics).The introduction of DNA analysis techniques has shown some complications of varicella-zoster to be more common than previously thought. For example, sporadic meningoencephalitis (ME) caused by varicella-zoster was regarded as rare disease, mostly related to childhood chickenpox. However, meningoencephalitis caused by varicella-zoster is increasingly recognized as a predominant cause of ME among immunocompetent adults in non-epidemic circumstances.Diagnosis of complications of varicella-zoster, particularly in cases where the disease reactivates after years or decades of latency, is difficult. A rash (shingles) can be present or absent. Symptoms vary, and there is a significant overlap in symptoms with herpes-simplex symptoms.Although DNA analysis techniques such as polymerase chain reaction (PCR) can be used to look for DNA of herpesviruses in spinal fluid or blood, the results may be negative, even in cases where other definitive symptoms exist. Notwithstanding these limitations, the use of PCR has resulted in an advance in the state of the art in our understanding of herpesviruses, including VZV, during the 1990s and 2000s. For example, in the past, clinicians believed that encephalitis was caused by herpes simplex and that people always died or developed serious long-term function problems. People were diagnosed at autopsy or by brain biopsy. Brain biopsy is not undertaken lightly: it is reserved only for serious cases that cannot be diagnosed by less invasive methods.
Liebenberg syndrome is a rare autosomal genetic disease that involves a deletion mutation upstream of the PITX1 gene, which is one thats responsible for the bodys organization, specifically in forming lower limbs. In animal studies, when this deletion was introduced to developing birds, their wing buds were noted to take on limb-like structures.The condition was first described by Dr. F. Liebenberg in 1973 while he followed multiple generations of a South African family, but it has since been noticed in other family lineages across the world. Symptoms and signs
People who are affected by Liebenberg Syndrome suffer from three main symptoms:
Dysplasia (improper formation) of the bony components of the elbow
Abnormal shape of carpal bones
Brachydactyly, a symptom where the fingers and toes are shorter than normal. Phenotype
People with Liebenberg Syndrome have normal overall body structure. Their morphological differences are in both of their distal humeri, elbows, hands and wrists. The elbows are enlarged with abnormally large olecranons and radial heads. Patients have relatively fixed elbow positions and are therefore unable to pronate or supinate their forearms. Their wrists are also limited in their active movements and have very prominent ulnar sides of the joints. The fingers adopt toe-like structures. Brachydactyly and camptodactyly occur; fingers are short and abnormally bent. These changes in finger shape result in small club shaped appendages. Motion is reduced in all digital joints of the hand. Genetics
Liebenberg Syndrome follows an autosomal dominant mode of inheritance, whereby heterozygotes with this mutation express the disease phenotype.