Jun Matsunaga

Acral pseudolymphomatous angiokeratoma of children (APACHE): a case report and immunohistological study

Acral pseudolymphomatous angiokeratoma of children (APACHE) is a new clinical entity that is characterized by angiomatous papules on the extremities. We report a case APACHK in a 14‐year‐old Japanese girl with asymptomatic red and violaceous papules and nodules on the ring finger of the left hand.

A Splicing Mutation of the Tyrosinase Gene Causes Yellow Oculocutaneous Albinism in a Japanese Patient with a Pigmented Phenotype

Background: Yellow oculocutaneous albinism (OCA) that is caused by tyrosinase gene mutations shows two characteristics: extreme hypopigmentation at birth and the eventual development of yellow or blond hair. Objective: We studied a Japanese girl who had brown hair, a lighter skin color than her unaffected family and brown eyes at 9 months of age. Methods: We performed direct sequencing analyses of the tyrosinase gene in her genomic DNA. Results: The patient was a compound heterozygote for the +ΔC310 mutation (known to result in absent melanogenic activity) and a second t→a transition at the 3′ end of intron 2. Conclusion: The t→a transition has previously been reported as a splicing mutation in other Caucasian patients with a typical yellow OCA phenotype. However, this patient showed much more pigmentation than that reported in Caucasians. Therefore, we estimate that the mild phenotype results from her genetic pigment background.

Sequence-Based Diagnosis of Tyrosinase-Related Oculocutaneous Albinism: Successful Sequence Analysis of the Tyrosinase Gene from Blood Spots Dried on Filter Paper

Background: A large number of mutations of the tyrosinase gene result in oculocutaneous albinism (OCA). Therefore, at present, sequence analysis of the tyrosinase gene has become necessary to diagnose OCA patients and their relatives. Objective: The aim of this study was to facilitate the sequence-based diagnosis of tyrosinase-related OCA by using small amounts of the patient’s blood. Methods: Blood spots dried on filter papers were used as sources of genomic DNA. The exons and flanking regions of the tyrosinase gene were amplified by polymerase chain reaction (PCR) and were directly sequenced in both directions. Results: We successfully amplified all exons of the tyrosinase gene by PCR and were able to characterize compound heterozygous mutations of R278X and +ΔC310 in the patient’s gene. Conclusion: Recent advances of PCR-related technology allowed us to use fairly limited samples of blood for sequence analysis of the tyrosinase gene.

Delayed development of foreign body granuloma from an implanted permanent cardiac pacemaker.

We report a case of a late‐developing cutaneous mass on the chest wall that proved to be non‐specific mixed cell granuloma adjacent to the lead‐electrode parts of a permanent cardiac‐pacemaker that had been implanted in the left chest of an 81‐year‐old man 6 years previously. The lesion was treated by cardiac surgeons, whose management consisted of cutting only the intradermal part of the lead‐electrodes followed by tissue curettage, leaving the other portion embedded in the subendocardium because its removal could cause serious complications. Dermatologists should be alert to such late complications of embedded permanent pacemakers. Their removal requires close cooperation with cardiac surgeons to avoid unexpected complications.

A novel mutation of the tyrosinase gene causing oculocutaneous albinism type 1 (OCA1)

Tyrosinase is a rate-limiting enzyme in the melanin biosynthetic pathway and a complete defect of the enzyme activity caused by homozygous mutations of the tyrosinase gene is well known to result in tyrosinase-negative oculocutaneous albinism (OCA1A) patients who never develop any melanin pigment in the skin, hair and eyes throughout life. In this paper, we report a novel missense substitution, R239W(CGG --> TGG) of the tyrosinase gene in a patient with tyrosinase-negative OCA.

Exclusion of linkage between dyschromatosis symmetrica hereditaria and chromosome 9

Dyschromatosis symmetrica hereditaria (DSH) is an autosomal dominant pigmentary disorder, first reported by Toyama in 1910. It is characterized by a mixture of hypopigmented and hyperpigmented macules of various sizes on the backs of the hands and feet. The disease gene of DSH and its chromosomal localization have not yet been identified. A family with DSH and idiopathic torsion dystonia (ITD), a rare neurological disease, was recently reported. Therefore, we speculated that there was a linkage between the DSH gene and the ITD gene, named DYT1 and localized on chromosome 9, and performed linkage analysis between DSH and microsatellite markers on chromosome 9 in three Japanese DSH families (36 patients in total). We obtained a LOD score of < -2 over the whole region of chromosome 9 encompassing DYT1. Thus, we conclude that there is no linkage between DSH and DYT1 as well as any region of chromosome 9.

CCR4 Expression by Atypical T Cells in Systemic Pilotropic Lymphoma: Its Behavior under Treatment with Interferon Gamma, Topical PUVA and Systemic Retinoid

We describe an 88-year-old Japanese patient with pilotropic T cell lymphoma involving the peripheral blood as well as lymph nodes. This patient presented with multiple red follicular papules, confluent, infiltrated erythematous plaques and nodules. Moreover, he was conspicuous for the presence of total alopecia of the scalp and eyebrows. Histopathologically, the lesional skin showed dense follicular and perifollicular infiltrates of atypical lymphocytes. The flow cytometry disclosed the presence of weakly CD4+ CCR4+ cell populations that would not be detected in the peripheral blood from healthy controls. The patient responded well to topical PUVA and systemic etretinate (retinoid-PUVA) and intravenous IFN-γ. Parallel with the decrease in atypical cells in the peripheral blood, the percentage of weakly CD4+ CCR4+ T cells declined. However, about 1 week after we discontinued this treatment because of the side effects, the lymph node swelling became prominent, and, 4 weeks later, the patient died before restarting any specific chemotherapy.

Electron microscopic DOPA reaction test for oculocutaneous albinism

Abstract Oculocutaneous albinism (OCA) is an autosomal recessive disorder in which the biosynthesis of melanin is reduced or absent in skin, hair and eyes. Tyrosinase-related OCA (OCA1) is caused by mutations in the tyrosinase gene. Tyrosinase-negative OCA (OCA1A) is the most severe phenotype in which tyrosinase catalytic activity is completely lost, resulting in no mature melanin pigment. Yellow OCA (OCA1B) varies from very little pigment associated with whitish-blond hair to nearly normal pigment with dark-blond hair and skin. We determined the tyrosinase activity in melanocytes by the electron microscopic dihydroxyphenylalanine (EM-DOPA) reaction test using skin samples and analyzed tyrosinase gene mutations in nine Japanese patients with OCA. In 18 alleles of nine patients, the OCA1A-associated mutations, P310insC, R77Q and R278X, were found in seven, three and one alleles, respectively. Five patients who had these mutations in both alleles showed white hair, blue eyes and white skin and demonstrated no tyrosinase activity by the EM-DOPA reaction test. Three patients who had no tyrosinase gene mutation showed tyrosinase activity and heterogeneous clinical features. One patient in whom only an R77Q OCA1A mutation was found in one allele demonstrated a reduced tyrosinase activity, indicating OCA1B. This patient had white hair at birth, but it had turned blond by the age of 1 year. These results indicate that the EM-DOPA reaction test provides clear information on the status of tyrosinase activity which is essential for the identification of the disease subtype which in turn is important for the prognosis of patients with OCA.

Detection of point mutations in human tyrosinase gene by improved allele‐specific amplification

Abstract Allele‐specific amplification (ASA) is a simple and non‐radioactive technique for detecting known point mutations that produce genetic diseases. Although this technique is based on the specific amplification of the target allele by a polymerase chain reaction (PCR) with allele‐specific primers, the specificity of the amplification may depend on various PCR conditions. To avoid non‐specific amplification which leads to false‐positive results in ASA, we modified both the normal and mutant allele‐specific primers so that they would have one constant base mismatch, located at the penultimate 3′ position. We confirmed that our modification could inhibit such unfavorable amplification by using as templates genomic DNAs of patients affected with tyrosinase‐negative oculocutaneous albinism (OCA). We then analyzed new patients affected with tyrosinase‐negative OCA, and based the diagnosis on both the results of a clinical examination and those of a hair bulb test using ASA with the modified allele‐specific primers. The results indicated that more than 3 alleles of the tyrosinase gene with a pathological mutation existed in Japanese patients.

R278TER AND P431L MUTATIONS OF THE TYROSINASE GENE EXIST IN JAPANESE PATIENTS WITH TYROSINASE-NEGATIVE OCULOCUTANEOUS ALBINISM

We examined the tyrosinase gene of two Japanese patients with tyrosinase-negative oculocutaneous albinism by allele-specific amplification analysis on two known point mutations in Japanese, and the results indicated that they were compound heterozygouts, namely, one allele of the tyrosinase gene harbored one of two known mutations and another allele probably had a mutation unknown in Japanese patients. Therefore, we have cloned and sequenced the tyrosinase gene of the two patients and identified two different point mutations. One is a nonsense mutation, codon 278CGA (Arg) to TGA (TER), and the other is a substitution mutation, codon 431CCA (Pro) to CTA (Leu). However, these same mutations have already been observed in a Guyanan and a Moroccan Jewish patient, and in an Indo-Pakistani patient, respectively.