Measles in a Patient with Presumed Immunity - Los Angeles County, 2015.

On February 14, 2015, patient A, aged 17 years, was seen in an emergency department for evaluation of reactive airway disease. In the waiting room at the same time were two siblings, aged 6 months, presenting with fever and rash; these two children (patients B and C) were later confirmed to have measles. Patient A began a 5-day course of oral prednisone (50 mg per day); however, symptoms continued, and patient A returned to the emergency department the next day and received 125 mg of intravenous (IV) methylprednisolone. Patient A had documentation of receipt of 2 doses of measles, mumps, and rubella (MMR) vaccine at ages 12 months and 4 years.

Dynamics of the rhomboid-like protein RHBDD2 expression in mouse retina and involvement of its human ortholog in retinitis pigmentosa.

The novel rhomboid-like protein RHBDD2 is distantly related to rhomboid proteins, a group of highly specialized membrane-bound proteases that catalyze regulated intramembrane proteolysis. In retina, RHBDD2 is expressed from embryonic stages to adulthood, and its levels show age-dependent changes. RHBDD2 is distinctly abundant in the perinuclear region of cells, and it localizes to their Golgi. A glycine zipper motif present in one of the transmembrane domains of RHBDD2 is important for its packing into the Golgi membranes. Its deletion causes dislodgment of RHBDD2 from the Golgi. A specific antibody against RHBDD2 recognizes two forms of the protein, one with low (39 kDa; RHBDD2(L)) and the other with high (117 kDa; RHBDD2H) molecular masses in mouse retinal extracts. RHBDD2(L) seems to be ubiquitously expressed in all retinal cells. In contrast, RHBDD2H seems to be present only in the outer segments of cone photoreceptors and may correspond to a homotrimer of RHBDD2(L). This protein consistently co-localizes with S- and M-types of cone opsins. We identified a homozygous mutation in the human RHBDD2 gene, R85H, that co-segregates with disease in affected members of a family with autosomal recessive retinitis pigmentosa. Our findings suggest that the RHBDD2 protein plays important roles in the development and normal function of the retina.

ZBED4, a BED-type zinc-finger protein in the cones of the human retina.

PURPOSE: To characterize the ZBED4 cDNA identified by subtractive hybridization and microarray of retinal cone degeneration (cd) adult dog mRNA from mRNA of normal dog retina. METHODS: The cDNA library obtained from subtractive hybridization was arrayed and screened with labeled amplicons from normal and cd dog retinas. Northern blot analysis was used to verify ZBED4 mRNA expression in human retina. Flow cytometry sorted peanut agglutinin (PNA)-labeled cones from dissociated mouse retinas, and quantitative RT-PCR (QPCR) was used to measure ZBED4 mRNA levels in these cone cells. Immunohistochemistry localized ZBED4 in human retinas. Expression of ZBED4 mRNA transiently transfected into HEK293 cells was analyzed by immunofluorescence. ZBED4 subcellular localization was determined with Western blot analysis. RESULTS: One of 80 cDNAs differentially expressed in normal and cd dog retinas corresponded to a novel gene, ZBED4, which is also expressed in human and mouse retinas. ZBED4 mRNA was found to be present in cone photoreceptors. When ZBED4 cDNA was transfected into HEK293 cells, the expressed protein showed nuclear localization. However, in human retinas, ZBED4 was localized to cone nuclei, inner segments, and pedicles, as well as to Müller cell endfeet. Confirming these immunohistochemical results, the 135-kDa ZBED4 was found in both the nuclear and cytosolic extracts of human retinas. ZBED4 has four predicted DNA-binding domains, a dimerization domain, and two LXXLL motifs characteristic of coactivators/corepressors of nuclear hormone receptors. CONCLUSIONS: ZBED4 cellular/subcellular localization and domains suggest a regulatory role for this protein, which may exert its effects in cones and Müller cells through multiple ways of action.

Translational regulation of the rod photoreceptor cGMP-phosphodiesterase: the role of the 5'- and 3'-untranslated regions.

We have established earlier that rod photoreceptor cGMP-phosphodiesterase (PDE6) alpha and beta subunits are equally represented in the retina at the protein level and have similar turnover rates. mRNA quantification revealed five PDE6beta messages for every PDE6alpha transcript pointing at post-transcriptional regulation of PDE6alpha and PDE6beta expression. Indeed, the wild-type PDE6alpha mRNA was translated 5-fold more efficiently than that of PDE6beta. The coding regions of these subunits had a major contribution in this process. Here, we extend our study of translational regulation of PDE6 subunits and present a detailed analysis of the role of PDE6alpha and PDE6beta 5'- and 3'-UTRs (untranslated regions) in this process. We showed that both the short and long PDE6beta 5'-UTRs lead to more efficient protein synthesis than the PDE6alpha 5'-UTR. The 3'-UTRs of PDE6alpha and PDE6beta stimulated translation by approximately 2- and 3-fold, respectively. However, the positive effect of the PDE6alpha or PDE6beta 3'-UTRs was not observed when these regions were placed in constructs containing the 5'-UTR of the corresponding PDE6 subunit. Furthermore, it appears that PDE6alpha 5'- and 3'-UTRs may be involved in a base pairing interaction that reduces the efficiency of protein synthesis. Finally, using progressive deletion analysis of the PDE6alpha 5'-UTR, we have identified several regions that have significant contribution in regulation of protein synthesis. Based on these and earlier published data, it can be stated that an equimolar level of PDE6alpha and PDE6beta synthesized from different amounts of mRNA (ratio of PDE6alpha to PDE6beta mRNA in the retina is 1:5) is achieved as a result of combinatorial effects of 5'-UTRs and coding regions of PDE6alpha and PDE6beta mRNAs on translational regulation.

A substitution of G to C in the cone cGMP-phosphodiesterase gamma subunit gene found in a distinctive form of cone dystrophy.

OBJECTIVE: To identify genes responsible for cone dystrophies and determine the functional consequences of their underlying mutations. DESIGN: Case-control study. PARTICIPANTS: Two hundred forty unrelated patients diagnosed with cone dystrophy, cone-rod dystrophy, macular dystrophy, macular degeneration, or Stargardt disease, 95 control individuals, and 2 unrelated families with a distinctive type of cone dystrophy. METHODS: The DNAs of the 240 probands were screened for sequence variants in the PDE6H gene (that encodes the inhibitory gamma-subunit of cone cyclic guanosine monophosphate [cGMP]-phosphodiesterase [PDE]) by single-strand conformation polymorphism electrophoresis. The effect of a nucleotide substitution in the DNA of a patient on gene expression efficiency was analyzed by in vitro transcription/translation. MAIN OUTCOME MEASURES: Cone-specific gene variants, fundus, visual field and electroretinogram (ERG) findings, and protein synthesis efficiency. RESULTS: We found a heterozygous G to C substitution in the 5' untranslated region (UTR) of the PDE6H gene in the DNA of a patient with a distinctive form of cone dystrophy, her sibling, and their father. This rare form of disease is very different in manifestation from other cone dystrophies and has been described as "cone dystrophy with nyctalopia and supernormal rod responses," "cone dystrophy with supernormal scotopic ERGs" and "supernormal and delayed rod ERG syndrome." Among the 240 patients that we studied, only 1 proband had the G to C variant. Furthermore, none of the 95 controls used in this study had this nucleotide change. We also determined that the PDE6H variant was not present in another family affected with this particular type of cone dystrophy. Because the 5' UTR of mRNAs plays a critical role in the regulation of protein synthesis, we determined the effect of the G to C change in this process. By use of in vitro transcription/translation experiments, we demonstrated that this substitution could lead to an increase in PDE6H gene expression. CONCLUSIONS: Our results indicate that mutations in the PDE6H gene are not common, because only 1 of 240 patients with cone dystrophy showed a single nucleotide substitution in the 5' UTR of PDE6H mRNA that could be associated with the disease. If the effect of the G to C substitution we observed in vitro also occurs in vivo, it will lead to PDE6H overexpression in the photoreceptors. Excess of PDEgamma may affect normal cone cGMP-PDE function by inhibiting the catalytic PDEalpha,beta activity and lead to pathogenic elevation of cGMP and eventual degeneration of cone photoreceptors.