ABSTRACT
A number of murine cataract mutations have been localized to chromosome 1 close to the gamma-crystallin gene cluster (Cryg) (Everett et al., 1994, Genomics 20: 429-434; Löster et al., 1994, Genomics 23: 240-242). Based on the size of the mapping or allelism tests they have not been shown to be genetically distinct and have been assigned to locus symbol Cat2. Here we assign three mutations to the respective gamma-crystallin gene. Using a systematic candidate gene approach to analyze the entire Cryg cluster, an A-->G transition was found in exon 2 of Cryga for the ENU-436 mutation and is designated Cryga1Neu. The mutant allele Crygbnop (formerly Cat2(nop)) is caused by a replacement of 11 bp by 4 bp in the third exon of Crygb, while a C-->G transversion in exon 3 of Cryge has been found for the Cryget (formerly Cat2(t)) mutation. For the mutation Cryga1Neu, an Asp-->Gly exchange is deduced, whereas the mutations Crygbnop and Cryget lead to the formation of in-frame stop codons and give rise to truncated proteins of 144 and 143 amino acids, respectively. The effects of the mutations upon gamma-crystallin structure are likely to be quite different. The Cryga1Neu mutation is expected to affect the link between Greek-key motifs 2 and 3, whereas both Crygbnop and Cryget mutations are supposed to truncate the fourth Greek-key motif. All three mutations are predicted to alter protein folding of the gamma-crystallins and result in lens cataract, but the phenotype for each is quite distinctive.
Subject(s)
Cataract/genetics , Crystallins/genetics , Genes/genetics , Amino Acid Sequence , Animals , Base Sequence , DNA Primers , Female , Gene Amplification , Gene Deletion , Male , Mice , Mice, Inbred C3H , Mice, Mutant Strains , Molecular Sequence Data , Multigene Family/genetics , Mutagenesis, Insertional , Mutation/genetics , Point Mutation , Polymerase Chain Reaction , Sequence Homology, Amino Acid , Sequence Homology, Nucleic AcidABSTRACT
Ten cases of acute carpal tunnel syndrome (ACTS) and six cases of nerve contusion were identified in patients with acute median neuropathy associated with blunt wrist trauma. The patients with ACTS initially had normal sensation and subsequently developed objective sensory loss (2-point discrimination greater than 15 mm) in the median nerve distribution associated with severe wrist pain. Patients with nerve contusion injuries had immediate sensory loss and symptoms were nonprogressive. Wick catheter measurements of the carpal canal pressure were used in seven patients to help distinguish ACTS (pressure greater than 40 mm Hg) from nerve contusion. The interstitial carpal tunnel pressure was elevated an average of 52 mm Hg in four of five patients with ACTS but was normal in two patients with nerve contusion. Four of five patients who underwent carpal tunnel release within 40 hours of the onset of numbness had normal 2-point discrimination within 96 hours. The results of this study and review of the literature reflect the urgency of carpal tunnel release in ACTS. Neuropathy, secondary to nerve contusion without coexisting ACTS, may be treated initially by observation. Acute carpal tunnel syndrome must be distinguished from nerve contusion as a cause of acute posttraumatic median neuropathy.
Subject(s)
Carpal Tunnel Syndrome/etiology , Wrist Injuries/complications , Acute Disease , Adolescent , Adult , Carpal Tunnel Syndrome/surgery , Child , Contusions , Emergencies , Female , Humans , Male , Median Nerve/injuries , Middle Aged , Retrospective Studies , Time FactorsABSTRACT
A case of acute carpal tunnel syndrome secondary to septic arthritis of the wrist is reported. Treatment consisted of carpal tunnel release, incision and drainage of the wrist joint, intravenous injection of antibiotics, and delayed primary closure. The infection resolved and median nerve function promptly returned to normal. We believe this is the first report of septic arthritis of the wrist as a cause of acute carpal tunnel syndrome.
