Kohji Kiwaki

Zinc and IGF-I concentrations in pregnant women with anemia before and after supplementation with iron and/or zinc.

OBJECTIVE The objective of our study was to investigate zinc (Zn) status and effects of Zn supplementation in relation to insulin-like growth factor-I (IGF-I) and iron deficiency anemia in pregnant women. The role of Zn and IGF-I in hematologic abnormalities has remained unclear. METHODS Thirty-eight Japanese women, when examined at the second trimester of pregnancy, had hemoglobin concentrations below 11.0 g/dL and 32 of 38 had normocytic erythrocytes. These 38 women were divided into three groups, and we compared the hematological status and serum IGF-I levels before and after iron (Group A) or Zn (Group B) or iron plus Zn (Group C) supplementation. RESULTS The concentrations of hemoglobin (Hb) did not change in groups A and B. In group C, Hb levels were significantly increased from 10.3+/-0.3 to 11.0+/-0.6 g/dL. Furthermore, numbers of RBC and reticulocytes also increased significantly. Concentrations of iron, IGF-I and total iron binding capacity (TIBC) were increased, and concentrations of erythropoietin were decreased, but not statistically. There were significant positive correlations between increases in IGF-I and increases in Hb and RBC in the Zn administered groups. CONCLUSION Zn status to some extent can account for hematological abnormalities in pregnant women. Zn derived IGF-I has a role in the regulation of hematopoiesis in pregnant women.

Phenotypic variability in male patients carrying the mutant ornithine transcarbamylase (OTC) allele, Arg40His, ranging from a child with an unfavourable prognosis to an asymptomatic older adult.

In five different Japanese families, we identified six male hemizygotes (aged 6, 9, 15, 17, 56, and 65 years) and a putative candidate (aged 48 years), carrying a mutant allele of the ornithine transcarbamylase (OTC) gene, a G to A substitution at nucleotide 119 in exon 2 generating histidine in place of arginine. OTC activity in the necropsied liver tissue was reduced to approximately 12% of the control and that of COS 1 cells transfected with Arg40His OTC cDNA was 10.2 +/- 1.8% of the control transfected with wild type OTC cDNA. Clinical features ranged from death during a hyperammonaemic attack (a 9 year old) to a 65 year old asymptomatic man. We consider that the amount of protein ingested by these subjects may be one predisposing factor leading to the manifestation of this disease.

Molecular and clinical analyses of Japanese patients with carbamoylphosphate synthetase 1 (CPS1) deficiency.

AbstractCarbamoylphosphate synthetase I deficiency (CPS1D) is a urea-cycle disorder characterized by episodes of life-threatening hyperammonemia. Correct diagnosis is crucial for patient management, but is difficult to make from clinical presentation and conventional laboratory tests alone. Enzymatic or genetic diagnoses have also been hampered by difficult access to the appropriate organ and the large size of the gene (38 exons). In this study, in order to address this diagnostic dilemma, we performed the largest mutational and clinical analyses of this disorder to date in Japan. Mutations in CPS1 were identified in 16 of 18 patients with a clinical diagnosis of CPS1D. In total, 25 different mutations were identified, of which 19 were novel. Interestingly, in contrast to previous reports suggesting an extremely diverse mutational spectrum, 31.8% of the mutations identified in Japanese were common to more than one family. We also identified two common polymorphisms that might be useful for simple linkage analysis in prenatal diagnosis. The accumulated clinical data will also help to reveal the clinical presentation of this rare disorder in Japan.

Novel mutations in five Japanese patients with 3-methylcrotonyl-CoA carboxylase deficiency

AbstractIsolated 3-methylcrotonyl-CoA carboxylase (MCC) deficiency appears to be the most frequent organic aciduria detected in tandem mass spectrometry (MS/MS) screening programs in the United States, Australia, and Europe. A pilot study of newborn screening using MS/MS has recently been commenced in Japan. Our group detected two asymptomatic MCC deficiency patients by the pilot screening and collected data on another three MCC deficiency patients to study the molecular bases of the MCC deficiency in Japan. Molecular analyses revealed novel mutations in one of the causative genes, MCCA or MCCB, in all five of the patients: nonsense and frameshift mutations in MCCA (c.1750C > T/c.901_902delAA) in patient 1, nonsense and frameshift mutations in MCCB (c.1054_1055delGG/c.592C > T) in patient 2, frameshift and missense mutations in MCCB (c.1625_1626insGG/c.653_654CA > TT) in patient 3, a homozygous missense mutation in MCCA (c.1380T > G/ 1380T > G) in patient 4, and compound heterozygous missense mutations in MCCB (c.569A > G/ c.838G > T) in patient 5. No obvious clinical symptoms were observed in patients 1, 2, and 3. Patient 4 had severe neurological impairment and patient 5 developed Reye-like syndrome. The increasing use of MS/MS newborn screening in Japan will further clarify the clinical and genetic heterogeneity among patients with MCC deficiency in the Japanese population.

Familial lethal inheritance of a mutated paternal gene in females causing X-linked ornithine transcarbamylase (OTC) deficiency

A Leu148Phe substitution of the ornithine transcarbamylase (OTC) gene was identified in a 2-year-old girl with OTC deficiency (14% of control). Her two elder sisters died in childhood of hyperammonemia, and the patient also died of OTC deficiency. Enzyme activity in Cos1 cells transfected by the mutant cDNA was undetectable, thereby indicating a definite pathogenic mutation. Familial gene analysis showed that the mother had wild-type OTC alleles on both X-chromosomes and the father was a mosaic for the mutant allele in his lymphocytes and spermatozoa. This clinical case shows that a somatic and germline mosaicism for a single-gene disorder led to an unusual pattern of X-linked inheritance in the family, and all three daughters in the family died of OTC deficiency. The possibility that inherited factors will lead to skewed X-inactivation needs to be considered.

Fatal cytomegalovirus myocarditis in a seronegative ALL patient

Fatal cytomegalovirus (CMV) myocarditis occurred in a 2 year old boy with acute lymphoblastic leukemia (ALL) in remission. The patient showed mild hepatic dysfunction and a rapid progress of pancytopenia after complete remission had been achieved. At the fifth week of complete remission, he presented signs of heart failure such as tachycardia, S4 gallop on auscultation and decreased ejection fraction on echocardiography. However, no significant electrocardiographic changes were recognized. In addition to the cardiac dysfunction, the patient presented a marked tachypnea and dyspnea associated with hypoxemia. These were dramatically improved by methylprednisolone pulse therapy (30 mg/kg per day, for 3 days) and CMV high titer immunoglobulin (400 mg/kg per day, for 3 days). On the sixth day after signs of respiratory failure were improved, the patient suddenly presented a paroxysmal atrial tachycardia followed by a fatal ventricular fibrillation. Although we could detect neither a specific IgM antibody, a significant increase of IgG antibody, nor CMV genome by DNA hybridization techniques during the course of the illness, microscopic examination of necropsy specimens of the heart showed a marked disruption and disintegration of muscle bands associated with cytomegalic inclusion bodies. Polymerase chain reaction (PCR) yielded a 305 bp amplification product in the heart and lung tissues, supporting the view that myocarditis was caused by CMV.

Gene therapy for ornithine transcarbamylase deficiency.

Ornithine transcarbamylase (OTC) deficiency in humans is the most common and severe inborn error of the urea cycle. Despite therapeutic advances, OTC deficiency remains without adequate treatment, hence mortality rates are high. In the two available strains of OTC‐deficient murine models, spf and spfash, researchers have tried to make genetic corrections by introducing the OTC gene. Transient but complete recovery of OTC was obtained in adult spfash mice and in OTC‐deficient human primary hepatocytes, using a recombinant adenoviral vector. These experiments represent a first step in the development of human gene therapy for OTC deficiency and other hepatic enzyme deficiencies.