Substitution Of Cysteine For Arginine Research Articles

A case of permeant neonatal diabetes with KCNJ11 mutation

Neonatal diabetes mellitus is considered when there is hyperglycaemia requiring insulin therapy. Phenotypically NDM is classified into three types-transient, permanent and syndromic forms. Permanent NDM-may start in new-born life and is mainly due single gene mutations-KCNJ11 and ABCC8. This mutation is almost 90% manageable with oral sulphonyl ureas. We report a case of Permanent NDM with KCNJ11 mutation who presented in diabetic Ketoacidosis at 4 months of age. Clinical genome sequencing revealed a heterozygous missense variation in exon 1 of the KCNJ11 gene (chr11: g.17387491G>A) that results in the amino acid substitution of cysteine for arginine at codon 201. She was initially treated with insulin for which she had poor glycaemic control. She responded well following the switch over to sulphonylureas with good compliance and has normal development.

Clinical and genetic characteristics of rare variants of acromelic skeletal dysplasias caused by mutations in the <i>FBN1</i> gene

BACKGROUND: Geleophysic dysplasia and acromicric dysplasia are rare hereditary diseases characterized by dwarfism and dysplastic skeletal features. In the literature, only a few cases of geleophysic dysplasia and acromicric dysplasia caused by mutations in the FBN1 gene are described.
 CLINICAL CASES: A description of the clinical and genetic characteristics of three female patients with acromelic dysplasias caused by three types of missense mutations in the FBN1 gene is presented. In two patients, on the basis of clinical manifestations and radiographic examination, acromicric dysplasia, and in one patient geleophysic dysplasia were diagnosed. It was shown that all identified mutations were localized in exons of the FBN1 gene encoding the amino acid sequence of the fifth domain, which has homology with transforming growth factor-beta.
 DISCUSSION: We have analyzed the clinical and genetic correlations to confirm the previously stated hypothesis about the occurrence of a severe phenotype of geleophysic dysplasia in patients with the c.5206T C mutation. This mutation is characterized by the replacement of cysteine by arginine in the position of the polypeptide chain leading to moderate clinical manifestations of acromicric dysplasia in patients with the c.5284 G A (p. Gly1762Ser). It was shown that the previously undescribed substitution c.5177G A (p.Gly1726Asp and another previously described mutation in this codon resulted in the replacement of glutamine with valine. This mutation causes the appearance of a less pronounced phenotype of AD.
 CONCLUSIONS: Based on the results of the examination of three Russian patients and analysis of clinical and radiographic parameters described in the literature, we reported that mutations in the FBN1 gene disrupted the amino acid sequence of the fifth like transforming growth factor-beta domain of fibrillin type 1. Importantly, these mutations are responsible for the occurrence of geleophysic dysplasia and acromicric dysplasia. However, the most severe clinical manifestations were observed in patients with mutations leading to the substitution of cysteine for arginine at the position of the polypeptide chain 1736. This may lead to affecting the transforming growth factor-beta signaling pathway.

Homozygous Missense Mutation on Exon 22 of PKHD1 Gene Causing Fatal Autosomal Recessive Polycystic Kidney Disease

AbstractAutosomal recessive polycystic kidney disease, described as a congenital hepatorenal fibrocystic syndrome, is a significant inherited cause of end stage renal failure in children with reported incidence of 1 in 20,000 live births. The clinical spectrum is wide. Antenatal findings of echogenic reniform enlarged kidneys associated with evidence of intrauterine renal failure in the form of severe oligoamnios are pathognomonic. Postnatal illness ranges from fatal respiratory failure due to pulmonary hypoplasia in neonates to chronic kidney disease in children, or later presentation of ductal plate malformation and portal hypertension. Advances in genetic diagnostic techniques have allowed recognition of genotypes. We report a novel homozygous missense variant on exon 22 of PKHD1 gene (chr6:51915067G > A; c.2167C > T) that results in the amino acid substitution of cysteine for arginine at codon 723 (p.Arg723Cys). The affected neonate presented with antenatal anhydramnios, classical radiological features, and severe hypoxic respiratory failure likely due to pulmonary hypoplasia and succumbed. The parents were found to be heterozygous carriers. Detection of the specific variant in the proband facilitated prenatal investigation in the next pregnancy.

CXXC5 variant in an immunodeficient patient with a progressive loss of hematopoietic cells

Partial loss of function variant in CXXC5 identified in an immunodeficient patient with progressive bone marrow failure, corrected by bone marrow transplant.

Insertional Mutagenesis Confounds the Mechanism of the Morbid Phenotype of a PLNR9C Transgenic Mouse Line

BackgroundA mouse line with heterozygous transgenic expression of phospholamban carrying a substitution of cysteine for arginine 9 (TgPLNR9C) under the control of α-myosin heavy chain (αMHC) promoter features dilated cardiomyopathy, heart failure, and premature death. Methods and ResultsDetermination of transgene chromosomal localization by conventional methods shows that in this line the transgenic array of 13 PLNR9C expression cassettes, arranged in a head-to-tail tandem orientation, have integrated into the bidirectional promoter of the αMHC (Myh6) gene and the gene for the regulatory noncoding RNA Myheart (Mhrt), both of which are known to be involved in cardiac development and pathology. Expression of the noncoding RNA Mhrt in TgPLNR9C mice exhibits profound deregulation, despite the presence of the second, intact allele. ConclusionsThe TgPLNR9C mouse strain is, in the best case, a functionally ambiguous phenocopy of the human PLNR9C heterozygote, because a similar constellation of genetically programmed events can not occur in a patient. Publications featuring “cardiac-specific overexpression” are focused on the phenotype and typically forgo the definition of the transgene integration site or transgene temporal expression profile, so caution should be exercised in attributing clinical relevance to pathologic phenomena observed in αMHC-driven transgenes.

A novel proteolipid protein 1 gene mutation causing classical type Pelizaeus-Merzbacher disease

Pelizaeus-Merzbacher disease (PMD) is a rare dysmyelinating disorder caused by mutations in the proteolipid protein 1 ( PLP1) gene. PMD is generally classified according to its clinical or pathological features into classical or connatal forms. We describe here a 19-year-old male with classical form PMD who presented with stridor and nystagmus in early infancy and whose psychomotor development has been severely delayed. Brain magnetic resonance imaging revealed white matter abnormalities typical of PMD. Direct sequencing of the PLP1 gene identified two nucleotide substitutions. One was a C-to-T transition at -31 in the 5’-flanking region of exon 1; the other was a novel point mutation, T-to-C transition in exon 4, which led to substitution of cysteine for arginine at residue 184. Because Cys184 forms a disulphide bridge with Cys228, the Cys184Arg mutation probably removes the bridge and changes the tertiary structure of PLP protein. A defective disulfide bond in PLP protein could be important in the pathogenesis of PMD.

Clinical and molecular characterization of a family with a dominant renin gene mutation and response to treatment with fludrocortisone

A family was identified with autosomal dominant inheritance of anemia, polyuria, hyperuricemia, and chronic kidney disease. Mutational analysis revealed a novel heterozygous mutation c.58T > C resulting in the amino acid substitution of cysteine for arginine in the preprorenin signal sequence (p.cys20Arg) occurring in all affected members. Effects of the identified mutation were characterized using in vitro and in vivo studies. Affected individuals were clinically characterized before and after administration of fludrocortisone. The mutation affects endoplasmic reticulum co-translational translocation and posttranslational processing, resulting in massive accumulation of non-glycosylated preprorenin in the cytoplasm. This affects expression of intra-renal RAS components and leads to ultrastructural damage of the kidney. Affected individuals suffered from anemia, hyperuricemia, decreased urinary concentrating ability, and progressive chronic kidney disease. Treatment with fludrocortisone in an affected 10-year-old child resulted in an increase in blood pressure and estimated glomerular filtration rate. A novel REN gene mutation resulted in an alteration in the amino acid sequence of the renin signal sequence and caused childhood anemia, polyuria, and kidney disease. Treatment with fludrocortisone improved renal function in an affected child. Nephrologists should consider REN mutational analysis in families with autosomal dominant inheritance of chronic kidney disease, especially if they suffer from anemia, hyperuricemia, and polyuria in childhood.

Identification and characterization of a novel ABCA3 mutation

Mutations in the gene coding for ATP-binding cassette protein A3 (ABCA3) are recognized as a genetic cause of lung disease of varying severity. Characterization of a number of mutant ABCA3 proteins has demonstrated that the mutations generally affect intracellular localization or the ability of the protein to hydrolyze ATP. A novel heterozygous mutation that results in the substitution of cysteine for arginine at amino acid 295 in ABCA3 was identified in a premature infant with chronic respiratory insufficiency and abnormal lamellar bodies. Sequencing of DNA performed in study participants demonstrated that this was a mutation and not a common variant. Plasmid vectors containing ABCA3 with the identified novel mutation tagged with green fluorescent protein on the carboxy terminus were generated. The effect of the mutation on protein function was characterized by examining the glycosylation state of the mutant protein in transiently transfected HEK293 cells and by examining ATP hydrolysis activity of the mutant protein with a vanadate-induced nucleotide trapping assay in stably transfected HEK293 cells. The ABCA3 protein containing the R295C mutation undergoes normal glycosylation and intracellular localization but has dramatically reduced ATP hydrolysis activity (12% of wild type). The identification of one copy of this novel mutation in a premature infant with chronic respiratory insufficiency suggests that ABCA3 haploinsufficiency together with lung prematurity may result in more severe, or more prolonged, respiratory failure.

Prevalence of myocilin gene mutations in a novel UK cohort of POAG patients

To identify the prevalence of myocilin gene mutations in a UK glaucoma cohort. Primary open-angle (POAG) and normal tension glaucoma patients were recruited from the Southampton University Hospital Trust Eye Clinic and satellite regional glaucoma clinics. Phenotype data relating to disease history and other potential risk factors were recorded and blood samples collected for each consenting participant. Point mutation analysis of the myocilin gene was carried out using six overlapping PCR fragments covering the entire coding sequence of the gene. A total of 316 POAG samples were examined of which 7 (2.2 %) tested positive for disease-causing mutations in this gene. One of these seven non-synonymous mutations represented a previously unreported amino-acid substitution of cysteine for arginine at codon 296 (p.R296C) of the myocilin protein. This study identifies a 2.2% prevalence of myocilin mutations in a cohort of ethnically homogenous glaucoma patients selected from a UK ophthalmic clinic. A novel myocilin mutation is also described. This study identifies that myocilin genetic screening is feasible in NHS glaucoma clinics for genetic counselling and cascade testing of relatives of patients affected by myocilin glaucoma.

The remarkably variable expressivity of CADASIL: report of a minimally symptomatic man at an advanced age

Sir, Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an adult-onset, dominantly inherited disorder caused by NOTCH3 mutations. It is characterized by recurrent subcortical infarctions, dementia, and less frequently, migraine and psychiatric symptoms. NOTCH3 has 33 exons, and most CADASIL-associated NOTCH3 mutations result in a gain or loss of one cysteine residue within a given extracellular epidermal growth factor (EGF)-like repeat domain and, in Caucasians, with a strong cluster in exon 3–6 encoding the first five EGF-like repeats [1]. The typical MRI features in CADASIL include multi-focal lacunar infarcts and diffuse T2-weighted hyperintensity of cerebral white matter with involvement of the anterior temporal lobes [1]. The presence of granular osmiophilic material (GOM), which is seen in close vicinity to the basement membrane of the smooth muscle cells of the arterioles on electron microscopy (EM), is pathognomonic for CADASIL [1]. Although the penetrance of MRI changes has been reported to be complete by 40 years of age [2], the spectrum of clinical phenotypes has remained elusive. Herein, we report the case of an 86-year-old minimally symptomatic male with CADASIL mutation, representing one extreme of the remarkably variable expressivity of CADASIL. The 86-year-old man had been doing very well before. His past history is only remarkable for heavy cigarette smoking without migraine or psychiatric symptoms. He came to our attention because of a mild numbness in the left hand following two falls 2 months earlier. The neurological examinations revealed only subtly increased deep tendon reflexes in the right biceps and brachioradialis. The brain MRI with gadolinium-enhanced magnetic resonance angiography (MRA) revealed a diffuse leukoencephalopathy without anterior temporal lobe involvement, one single and small lacunar infarct in the left putamen (Fig. 1a), and patent cerebral vessels. Subsequent mutational analysis of NOTCH3 uncovered a missense mutation, c. 1708C [ T, in exon 11, which putatively may result in a substitution of cysteine for arginine at amino acid 544 (R544C). The EM exam of a skin biopsy demonstrated the presence of characteristic GOM (Fig. 1b, c). His family history was unclear because of his early separation, at teenage, from the family and he has no children. He had received 7 years of education. His score of Mini-Mental State Examination (MMSE) was 27 out of 30 and the Cognitive Abilities Screening Instruments (CASI) was 81 out of 100. The cutoff scores of CASI in our population for the diagnosis of dementia in those who received 6 or more years of education is 79/80 [3]. NOTCH3 R544C has previously been reported manifesting typical CADASIL features [4, 5]. In the literature, the clinical manifestations of NOTCH3 mutations are enormously variable [6], with another report of a 14-yearold boy presenting with recurrent hemiplegia [7]. The observation in this patient highlights that, because the clinical manifestations may be extremely subtle, NOTCH3 Y.-C. Lee B.-W. Soong (&) Department of Neurology, National Yang-Ming University School of Medicine and Taipei Veterans General Hospital, #155, Sec.2, Li-Nung Street, Peitou District, Taipei 11217, Taiwan, ROC e-mail: bwsoong@vghtpe.gov.tw

Wild-type apo A-I and apo A-IMilano gene transfer reduce native and transplant arteriosclerosis to a similar extent

Apolipoprotein (apo) A-I(Milano) is an apo A-I mutant characterized by a cysteine for arginine substitution at position 173. Apo A-I(Milano) carriers have much less atherosclerosis than expected from their low plasma high-density lipoprotein cholesterol levels, suggesting that this mutant may have superior atheroprotective properties. Here, we compare the effect of hepatocyte-directed gene transfer of wild-type human apo A-I and human apo A-I(Milano) on endothelial progenitor cell (EPC) biology and on the progression of native atherosclerosis and allograft vasculopathy in C57BL/6 apo E(-/-) mice. Human apo A-I and apo A-I(Milano) transfer resulted in an equivalent increase of EPC number and function as well as EPC incorporation and endothelial regeneration in allografts and inhibited the progression of native atherosclerosis and allograft vasculopathy to a similar extent. In conclusion, the current head-to-head comparison indicates that human apo A-I(Milano) transfer is not superior compared to wild-type human apo A-I transfer.

Mutation Analysis of the VMD2 Gene in Thai Families with Best Macular Dystrophy

Background: To identify genetic mutations of the VMD2 gene in two Thai families with Best macular dystrophy. Materials and Methods: Ophthalmic examination including best-corrected visual acuity (BCVA), dilated fundus examination and fundus photography, and electro-oculography (EOG) was performed in two probands and their family members. Mutation screening of the VMD2 gene was performed by single-strand conformation polymorphism (SSCP) analysis followed by direct DNA sequencing of the abnormal exons. Results: The 58-year-old male proband demonstrated typical egg yolk-like macular lesion in both eyes. Mutational screening of VMD2 identified a band shift in exon 7, which was confirmed by direct DNA sequencing to be a G to A transition at position 724 bp. This novel missense mutation resulted in the change of an amino acid valine to methionine and was responsible for the abnormal Arden ratio in the proband's daughter. The second male proband age 25 had a characteristic egg yolk-like macular lesion in the left eye and a scrambled egg appearance in the right. Mutation analysis identified a C to T transition at position 652 bp in exon 6. This reported missense mutation led to an amino acid substitution of cysteine for arginine. The mutation was documented in the maternal grandmother, the mother, as well as the elder sister of the proband. Conclusions: The Val-242-Met mutation is associated with a late-onset visual disturbance and the Arg-218-Cys mutation was associated with marked intra-familial clinical variability of expression. Presymptomatic testing will be available to the family members at risk with high accuracy.

A polymorphism in the gene encoding procolipase produces a colipase, Arg92Cys, with decreased function against long-chain triglycerides

Type 2 diabetes mellitus is a multifactorial and polygenic disorder with increasing prevalence. Recently, a polymorphism in the gene encoding procolipase, a cysteine for arginine substitution at position 92, was associated with type 2 diabetes in two human populations. Because procolipase plays a critical role in dietary fat metabolism, polymorphisms that affect the function of procolipase could influence the development of type 2 diabetes. We hypothesized that the Arg92Cys polymorphism has functional consequences. To test our hypothesis, we expressed recombinant cysteine 92 (Cys92) procolipase in a yeast expression system and compared the function and stability of purified Cys92 with that of the more common arginine 92 (Arg92) procolipase. Cys92 fully restored the activity of bile-salt inhibited lipase with short- and medium-chain triglycerides but only had 50% of Arg92 function with long-chain triglycerides. After storage at 4 degrees C, Cys92 lost the ability to restore pancreatic triglyceride lipase activity with medium- and long-chain triglycerides. The loss of function correlated with the inability of Cys92 to anchor lipase on an emulsion surface and oxidation of the cysteine. No detectable degradation or intramolecular disulfide formation occurred in Cys92 after storage. Our findings demonstrate that the Arg92Cys polymorphism decreases the function of Cys92 colipase. This change may contribute to the development of type 2 diabetes.

Association of multiple vertebral hemangiomas and severe paraparesis in a patient with aPTENhamartoma tumor syndrome

The PTEN hamartoma tumor syndrome, manifestations of which include Cowden disease and Bannayan-Riley-Ruvalcaba syndrome, is caused by various mutations of the PTEN gene located at 10q23. Its major criteria are macrocephaly and a propensity to develop breast and thyroid cancers as well as endometrial carcinoma. Minor diagnostic criteria include hamartomatous intestinal polyps, lipomas, fibrocystic disease of the breasts, and fibromas. Mutations of PTEN can also be found in patients with Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum). The authors report the case of a 17-year-old girl who had a severe cyanotic cardiac malformation for which surgery was not advised and a heterozygous missense mutation (c.406T>C) in exon 5 of PTEN resulting in the substitution of cysteine for arginine (p.Cysl36Arg) in the protein, which was also found in her mother and sister. The patient presented in the pediatric emergency department with severe spastic paraparesis. A magnetic resonance imaging study of the spine showed vertebral hemangiomas at multiple levels, but stenosis and compression were maximal at level T5-6. An emergency T5-6 laminectomy was performed. The decompression was extremely hemorrhagic because the rapid onset of paraparesis necessitated prompt treatment, and there was no time to perform preoperative embolization. The patient's postoperative course was uneventful with gradual recovery. This represents the first report of an association of a PTEN mutation and multiple vertebral angiomas. The authors did not treat the remaining angiomas because surgical treatment was contraindicated without previous embolization, which in itself would present considerable risk in this patient with congenital cyanotic heart disease.

Recombinant apolipoprotein A-IMilano for the treatment of cardiovascular diseases

Apolipoprotein A-I(Milano) (apoA-I(M)) is a natural variant of apoA-I characterized by a cysteine for arginine substitution at position 173 of the primary sequence. ApoA-I(M) carriers have much less atherosclerosis than expected from their very low plasma high-density lipoprotein (HDL) cholesterol levels, suggesting that the variant might be protective. Synthetic HDL (sHDL) made with a recombinant form of the dimeric A-I(M) (A-I(M)/A-I(M)) and phospholipids given in single or multiple injections is effective in inducing the regression of atherosclerotic plaques, preventing arterial restenosis, and limiting cardiac dysfunction after ischemia/reperfusion injury. In a phase II trial in patients with acute coronary syndromes, a short-term treatment with A-I(M)/A-I(M) sHDL caused a remarkable reduction of atheroma burden. Although at early stages of drug development, A-I(M)/A-I(M) sHDL holds vast promise for the treatment of a variety of cardiovascular diseases in humans.

ApoA-I Milano/phospholipid Complexes Emerging Pharmacological Strategies and Medications for the Prevention of Atherosclerotic Plaque Progression

Epidemiologic and experimental observations suggest high density lipoprotein (HDL) has a protective effect against atherothrombotic vascular disease. These findings have stimulated considerable interest to promote HDL as a potential therapeutic strategy. Several exciting therapeutic strategies have recently emerged and currently are the focus of intense research interest. One approach is the direct administration of HDL or its components such as apolipoprotein A-I (apoA-I). Recently, much attention has focused on a naturally occurring variant of apoA-I, apoA-I(Milano) (apoA-IM) characterized by a cysteine for arginine substitution that is associated with low rates of vascular disease and significant longevity in its carriers, despite markedly reduced HDL and elevated triglyceride levels. The mutation alters the characteristics of the protein resulting in apoA-IM being functionally more effective than normal apoA-I. A number of animal and laboratory studies have demonstrated significant antiatherogenic, antiproliferative, antirestenotic, antiplatelet, antithrombotic, antiinflammatory, and antioxidant properties of apoA-IM. Furthermore, apoA-IM has been shown to promote reverse cholesterol transport, improve endothelial dysfunction and induce rapid mobilization of tissue cholesterol resulting in regression and alteration of plaque composition in animal models of atherosclerosis. Recently, a pilot clinical trial of recombinant apoA-IM demonstrated significant and rapid regression of atherosclerosis as measured by intravascular ultrasound in patients with acute coronary syndromes. These promising data provide the rationale for the development of reconstituted HDL utilizing recombinant apoA-IM as a potential therapeutic approach for atherothrombotic vascular disease in humans.

High Density Lipoprotein Administration: A New Therapeutic Modality for the Treatment of Cardiovascular Diseases

Apolipoprotein A-I (apoA-I) is a 243 amino-acid cysteine deficient protein, containing 10 amphipathic domains, that allow its binding to a lipid-rich surface. It is the major protein component of high-density lipoproteins (HDL). Each HDL contains 2 or 3 copies of apoA-I plus various combinations of additional apolipoproteins (e.g. apoE, apoA-IV, apoA-II), lipid transport proteins (e.g. CETP and PLTP), and surface acting enzymes (e.g. paraoxonase, LCAT, PAF). This heterogenous and dynamic class of lipoproteins mainly functions in reverse cholesterol transport, a process resulting in the net removal of excess cholesterol from tissues, to be transported to the liver for excretion. The apolipoprotein AIMilano (A-IMilano) is a rare and naturally occurring variant form of the native apoA-I. The A-IMilano variant was a chance discovery in an individual with very low HDL-cholesterol (7-10 mg/dL) compared to the normal human levels of 40-50 mg/dL. This clinical observation dates back 30 years, and was accompanied by similar findings in two of the probands children as well as in his father. Surprisingly, these carriers appeared to be remarkably free from any vascular abnormalities. Extensive studies led to the identification of the mutation, a Cysteine for Arginine substitution at position 173, i.e. the first description of a human apolipoprotein mutation associated to altered lipoprotein composition and metabolism. This led to an extensive evaluation of the population of Limone sul Garda for the presence of the mutation and the cardiovascular disease status of the population, confirming the earlier suggestion that this might be a protective variant. In the past 25 years some important additional insights were provided. Particularly, it could be shown that the HDL containing AIMilano is endowed with a remarkably enhanced capacity to remove cholesterol from tissues. "HDL therapy" is a novel and emerging area of therapeutic development in the cardiovascular field. It attempts to supplement and improve the vascular benefit exerted by other agents active on lipid metabolism, ie hypolipidemic drugs. Further, it takes advantage on novel techniques of coronary evaluation. A number or reports have examined the potential therapeutic properties of synthetic HDL prepared by complexing recombinant apo A-IMilano with phospholipids. The availability of synthetic HDL complexes containing recombinant apoA-IMilano has opened a new era of therapeutic management of coronary disease. Prototype HDL formulations of recombinant apoA-IMilano/phospholipid complexes have used dipalmitoylphosphatidylcholine (DPPC) or 1-palmitoyl-2-oleyl phosphatidylcholine (POPC) as phospholipid component. HDL containing apoAIMilano/ DPPC have clearly shown rapid regression of a focal carotid atheroma in a rabbit model. The mechanism of this very rapid effect appears to be associated with the cholesterol removing capacity and extended serum half-life of HDL containing A-IMilano. In a pilot study, ETC-216 (apoA-IMilano/POPC) similarly showed significant reduction of coronary plaque burden after five weekly treatments as assessed by intravascular ultrasound (IVUS) in patients with acute coronary syndromes. It is likely that additional safety, efficacy and dose regimen studies in a larger patient population will need to be performed to fully evaluate the potential of this agent as an "HDL therapy" product candidate. "HDL therapy" such as ETC- 216 is being evaluated for use with the current standard of care for patients with acute coronary syndromes, including the use of statins. Keywords: synthetic hdl, apolipoprotein a-iMilano, cardiovascular disease, atherosclerosis, ivus, recombinant proteins, regression, animal models

X-linked severe combined immunodeficiency syndrome: the first Korean case with gamma c chain gene mutation and subsequent genetic counseling.

X-linked severe combined immunodeficiency (X-SCID) is a rare, life-threatening immune disorder, caused by mutations in the γc chain gene, which encodes an essential component of the cytokine receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21. A 13-month-old boy with recurrent infections who had reduced serum immunoglobulin levels and decreased numbers of CD3, CD16/56 cells was evaluated for γc chain gene mutation and protein expression. The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP. The patient's mother was a heterozygous carrier. Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy. As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence. This is the first report of the molecular diagnosis of X-SCID in Korea. Genetic analysis of the γc chain gene is useful for definite diagnosis and genetic counseling for X-SCID.

Cell death triggered by a novel mutation in the alphaA-crystallin gene underlies autosomal dominant cataract linked to chromosome 21q.

Hereditary cataract is a clinically and genetically heterogeneous lens disease that accounts for a significant proportion of visual impairment and blindness in childhood. The alphaA-crystallin (CRYAA) gene (CRYAA) encodes a member of the small-heat-shock protein (sHSP) family of molecular chaperones and is primarily and abundantly expressed in the ocular lens. Here, we have used linkage analysis to identify a novel missense mutation in CRYAA that underlies an autosomal dominant form of 'nuclear' cataract segregating in a four-generation Caucasian family. A maximum two-point LOD score (Z(max)) of 2.19 (maximum recombination fraction, theta(max)=0) and multipoint Z(max) of 3.3 (theta(max)=0) was obtained at marker D21S1885. Haplotype analysis indicated that the disease gene lay in the approximately 2.7 Mb physical interval between D21S1912 and D21S1260 flanking CRYAA on 21q22.3. Sequence analysis identified a C --> T transition in exon 1 of CRYAA from affected individuals that was predicted to result in the nonconservative substitution of cysteine for arginine at codon 49 (R49C). Transfection studies of lens epithelial cells revealed that, unlike wild-type CRYAA, the R49C mutant protein was abnormally localized to the nucleus and failed to protect from staurosporine-induced apoptotic cell death. This study has identified the first dominant cataract mutation in CRYAA located outside the phylogenetically conserved 'alpha-crystallin core domain' of the sHSP family.

A Case of a Novel Mutant Vasopressin Receptor-Dependent Nephrogenic Diabetes Insipidus with Bilateral Non-Obstructive Hydronephrosis in a Middle Aged Man-Differentiation from Aquaporin-Dependent Nephrogenic Diabetes Insipidus by the Response of Factor VIII and von Willebrand Factor to 1-Deamino-8-D-Arginine Vasopressin Administration-

We describe a case of a novel mutant vasopressin 2 receptor (V2R)-dependent nephrogenic diabetes insipidus (NDI) with bilateral non-obstructive hydronephrosis in a middle aged man. This could be distinguished from aquaporin 2 (AQP2)-dependent NDI by the response of factor VIII and von Willebrand factor (vWF) to 1-deamino-8-D-arginine vasopressin (DDAVP) administration. A 47-year-old man was admitted to hospital because of polyuria, which had been present from infancy and was suspected of causing non-obstructive hydronephrosis. His mother's father, the older brother of his mother and his second daughter also all had polyuria. Sodium concentration, osmolality and vasopressin in blood were high, while sodium concentration and osmolality in urine were low. There were no changes in urine osmolality, factor VIII and vWF in response to DDAVP infusion. Neither was heart rate, diastolic blood pressure nor facial flushing affected. These findings suggested this case was V2R-dependent NDI rather than AQP2-dependent NDI. Molecular genetic analysis demonstrated that the patient had a V2R missense mutation involving a substitution of cysteine for arginine at position 104 (R104C) located in the first extracellular loop of the V2R. It was also found that the patient's mother and his second daughter were heterozygous for this R104C mutation.