Identification of pathogenic genetic variants in patients with acquired early-onset bilateral cataracts using next-generation sequencing.

BACKGROUND: Acquired early-onset bilateral cataracts can result from systemic etiologies or genetic disorders. METHODS: In this observational study, we analyzed individuals 18 months to 35 years of age with acquired bilateral cataracts via a next-generation sequencing panel of 66 genes to identify disease-causing genetic variants. RESULTS: Of 347 patients enrolled, 313 (90.2%) were <19 years (median, 8 years). We identified 74 pathogenic or likely pathogenic variants in 69 patients. Of the variants, we observed 64 single nucleotide variants (SNV) in 24 genes and 10 copy number variants (CNV) of varying size and genomic location. SNVs in crystallin genes were most common, accounting for 27.0% of all variants (20 of 74). Of those, recurrent variants included known cataract-causing variants CRYBA1 c.215+1G>A, observed in 3 patients, and CRYBA1 c.272_274delGAG, CRYBB2 c.463C>T and c.562C>T, and CRYAA c.62G>A, each observed in 2 patients. In 5 patients, we identified CNV deletions ranging from 1.32-2.41 Mb in size associated with 1q21.1 microdeletion syndrome. Biallelic variants in CYP27A1 were identified in two siblings, one as part of targeted follow-up family testing, who were subsequently diagnosed with cerebrotendinous xanthomatosis, a rare but treatable autosomal recessive disease that often presents with acquired early-onset bilateral cataracts. CONCLUSIONS: This study demonstrates the utility of genetic testing in individuals with acquired early-onset bilateral cataracts to help clarify etiology. Identification of causative genetic variants can inform patient management and facilitate genetic counseling by identifying genetic conditions with risk of recurrence in families.

Living with Cerebrotendinous Xanthomatosis: Patient, Caregiver, and Expert Perspectives.

In this article, patients with cerebrotendinous xanthomatosis (CTX) and caregivers detail their experience with lifelong symptoms, diagnosis, treatment and efficacy, and ongoing disease management. One patient and four caregivers describe the challenges associated with pursuing a correct diagnosis for years before testing confirmed a CTX diagnosis. They also detail their ongoing struggles and desire for greater access to physicians with CTX knowledge and to reliable online resources to continue their education about the disease and strategies for symptom management. The expert perspective is a direct response by three CTX researchers, including physicians who are treating patients with CTX in the United States and experts whose laboratories provide genetic and biochemical testing for CTX. They respond to many of the patient and caregiver concerns, including steps that are being taken to identify CTX earlier and provide access to confirmatory diagnostic testing sooner, and suggest the best online resources for CTX-related information and access to webinars and support groups. While the expert perspective is a direct response to the patient and caregiver authors' CTX journeys, it should be beneficial to any patient with CTX or their caregivers.

Treatment of cerebrotendinous xanthomatosis in pregnancy: Patient and physician perspectives.

Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive disorder of bile acid synthesis that presents with varied and progressive symptomology. Early treatment with chenodeoxycholic acid (CDCA) improves symptoms and slows degeneration. Patients with CTX are commonly recommended to discontinue CDCA treatment during pregnancy because of theoretical risks to the fetus, but patient and clinician concerns about the risks of stopping treatment cause uncertainty. Herein, we report the experiences and perspectives of two women with CTX from the time of diagnosis through pregnancy, as well as decisions regarding CDCA treatment during pregnancy. Before becoming pregnant, both women were concerned about potential risks to their newborns if they continued or stopped CDCA treatment during pregnancy. Reassurance from their CTX specialist was the primary factor in their decision to continue treatment during pregnancy. After pregnancies complicated by preeclampsia, one gave birth to a healthy infant and the other gave birth to an infant later diagnosed with periventricular leukomalacia. Neither experienced CDCA-related complications.

Prevalence of cerebrotendinous xanthomatosis among patients diagnosed with early-onset idiopathic bilateral cataracts: final analysis.

Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive bile acid synthesis disorder caused by pathologic variants in CYP27A1, a gene involved in bile acid synthesis. Impaired function in this gene leads to accumulation of plasma cholestanol (PC) in various tissues, often in early childhood, resulting in such clinical signs as infantile diarrhea, early-onset bilateral cataracts, and neurological deterioration. The current study aimed to identify cases of CTX in a population of patients with a greater CTX prevalence than the general population, to facilitate early diagnosis. Patients diagnosed with early-onset, apparently idiopathic, bilateral cataracts between the ages of 2 and 21 years were enrolled. Genetic testing of patients with elevated PC and urinary bile alcohol (UBA) levels was used to confirm CTX diagnosis and determine CTX prevalence. Of 426 patients who completed the study, 26 met genetic testing criteria (PC ≥ 0.4 mg/dL and positive UBA test), and 4 were confirmed to have CTX. Prevalence was found to be 0.9% in enrolled patients, and 15.4% in patients who met the criteria for genetic testing.

Blood Stream Infection Caused by Carbapenem-resistant Chryseobacterium indologenes Harboring blaNDM-1 Gene Isolated from a Tertiary Care Hospital in Tripura: An Emerging Threat.

OBJECTIVES: Chryseobacterium indologenes has recently been identified as an inherently drug-resistant organism, responsible for a wide spectrum of infections, mainly device-associated infections in hospital settings. The presence of carbapenem resistance due to blaNDM-1 metallo-ß-lactamase (MBL) gene further complicates the matter, leading to widespread dissemination of carbapenem resistance. This study aims to find out the presence of blaNDM-1 gene among C. indologenes strains causing bloodstream infections in a tertiary care hospital. MATERIALS AND METHODS: During 1 year of the study period, blood culture samples were collected from patients with features of bacteremia, and C. indologenes strains were isolated and identified as per protocol. Antibiotic sensitivity test was performed by using VITEK 2 Compact Automated AST machine (Biomerieux, France). Carbapenem-resistant strains were subjected to a combined disk diffusion test for detecting the presence of MBL enzyme. Strains positive for MBL production were subjected to a polymerase chain reaction (PCR) for detection of blaNDM-1 gene. RESULTS: Out of 21 strains isolated during the study period, 12 strains (57.1%) were carbapenem-resistant. Among them, seven strains (58.3%) were MBL producers. After PCR, 3 strains (42.9%) were found to be harboring blaNDM-1 gene Discussion: As per our knowledge, this is the first report of blaNDM-1 gene harboring C. indologenes strain from Northeast India. This shows the emerging therapeutic dilemma due to the narrowing of treatment options against bloodstream infections due to C. indologenes strains. Strict antimicrobial stewardship has to be implemented to prevent the further compounding of the problem.

Metallothionein isoform 3 expression inhibits cell growth and increases drug resistance of PC-3 prostate cancer cells.

BACKGROUND: The third isoform of metallothionein (MT-3) is overexpressed in prostate cancers and PIN lesions. The expression of MT-3 is highly variable but appears to correlate to Gleason score. The goal of the present study was to determine the effect of MT-3 overexpression on the growth of the PC-3 prostate cancer cell line. METHODS: PC-3 cells were stably transfected with either the MT-3 or MT-1E gene. Cell growth was determined by counting DAPI-stained nuclei, drug resistance by the colony formation assay, MT mRNA expression by reverse transcriptase-polymerase chain reaction, and MT protein by immunoblot. RESULTS: PC-3 cells that overexpress the MT-3 gene are growth inhibited compared with either untransfected cells, cells with blank vector, or cells with similar overexpression of the MT-1E gene. Furthermore, increased chemotherapeutic drug resistance occurred in PC-3 clones derived from MT-3- and MT-1E-transfected cells. CONCLUSION: The overexpression of MT-3 can influence the growth and chemotherapeutic drug resistance of the PC-3 prostate cancer cell line.

Transient induction of metallothionein isoform 3 (MT-3), c-fos, c-jun and c-myc in human proximal tubule cells exposed to cadmium.

Cadmium (Cd(+2)) has been shown to transiently increase the expression of mRNA for the third isoform of the metallothionein (MT-3) gene family in cultured human proximal tubule (HPT) cells. The goal of the present study was to further define the expression of MT-3 in mortal (HPT) and immortal (HK-2) cultures of HPT cells when exposed to lethal and sub-lethal concentrations of Cd(+2) under both acute and chronic time periods of exposure. Expression of MT-3 mRNA and protein was determined in cultured HPT cells and HK-2 cells using reverse-transcription-polymerase chain reaction (RT-PCR) and immuno-blotting, and expression of c-fos, c-jun and c-myc mRNA by RT-PCR. The results confirmed that exposure of the HPT cells to Cd(+2) induced a transient increase in MT-3 mRNA and extended the induction to include a subsequent transient increase in the level of the MT-3 protein. The induction of MT-3 was rapid and returned to control values within 48 h of exposure despite the continued presence of lethal and sublethal concentrations of Cd(+2). It was also demonstrated that the pattern of expression of MT-3 mRNA was similar to that of the early response genes, c-fos, c-jun and c-myc. It was shown that the HK-2 cells did not express MT-3 when exposed to Cd(+2), but had similar expression of the c-fos, c-jun and c-myc genes. The results demonstrate that MT-3 expression is metal responsive in HPT cells.