Germline KRAS and BRAF mutations in cardio-facio-cutaneous syndrome.

Cardio-facio-cutaneous (CFC) syndrome is characterized by a distinctive facial appearance, heart defects and mental retardation. It phenotypically overlaps with Noonan and Costello syndrome, which are caused by mutations in PTPN11 and HRAS, respectively. In 43 individuals with CFC, we identified two heterozygous KRAS mutations in three individuals and eight BRAF mutations in 16 individuals, suggesting that dysregulation of the RAS-RAF-ERK pathway is a common molecular basis for the three related disorders.

Germline mutations in HRAS proto-oncogene cause Costello syndrome.

Costello syndrome is a multiple congenital anomaly and mental retardation syndrome characterized by coarse face, loose skin, cardiomyopathy and predisposition to tumors. We identified four heterozygous de novo mutations of HRAS in 12 of 13 affected individuals, all of which were previously reported as somatic and oncogenic mutations in various tumors. Our observations suggest that germline mutations in HRAS perturb human development and increase susceptibility to tumors.

Comprehensive mutation analysis of GLDC, AMT, and GCSH in nonketotic hyperglycinemia.

Nonketotic hyperglycinemia (NKH) is an inborn error of metabolism characterized by accumulation of glycine in body fluids and various neurological symptoms. NKH is caused by deficiency of the glycine cleavage multi-enzyme system with three specific components encoded by GLDC, AMT, and GCSH. We undertook the first comprehensive screening for GLDC, AMT, and GCSH mutations in 69 families (56, six, and seven families with neonatal, infantile, and late-onset type NKH, respectively). GLDC or AMT mutations were identified in 75% of neonatal and 83% of infantile families, but not in late-onset type NKH. No GCSH mutation was identified in this study. GLDC mutations were identified in 36 families, and AMT mutations were detected in 11 families. In 16 of the 36 families with GLDC mutations, mutations were identified in only one allele despite sequencing of the entire coding regions. The GLDC gene consists of 25 exons. Seven of the 32 GLDC missense mutations were clustered in exon 19, which encodes the cofactor-binding site Lys754. A large deletion involving exon 1 of the GLDC gene was found in Caucasian, Oriental, and black families. Multiple origins of the exon 1 deletion were suggested by haplotype analysis with four GLDC polymorphisms. This study provides a comprehensive picture of the genetic background of NKH as it is known to date.

A study of transdermal fentanyl in cancer pain at Aichi-Cancer Center.

In Japan, transdermal fentanyl (Durotep Patch) was launched in March 2002, and it was regarded as making opioid rotation possible. When changing from morphine to transdermal fentanyl, the efficacy ratio of 1:150 is used in Japan as well as in many other countries. However, the ratio of 1:100 is used in Germany. As a result, a dose increase in transdermal fentanyl is often required to control pain. We studied transdermal fentanyl use in the Aichi Cancer Center (ACC) to investigate the actual conversion ratio and appropriate switching by following up 144 patients (81 men, 63 women) who had received transdermal fentanyl in the ACC from March 19, 2002, to April 30, 2003. Transdermal fentanyl improved pain control in patients who had difficulty in tolerating oral medication or in continuing morphine because of side effects. Regression analysis indicated that the efficacy ratio of oral morphine to transdermal fentanyl was 1:78. As the fentanyl dosage was excessive even in some patients who followed the recommended morphine/fentanyl conversion of 150:1, it is dangerous to use the conversion ratio of 78:1 at first. Morphine side effects were reduced in some patients who changed to transdermal fentanyl, but there was no reduction in those who needed high-dose morphine for rescue analgesia. Therefore it is safe and effective to use low-dose transdermal fentanyl in the beginning and to control pain promptly using rescue morphine based on the present recommended dosage. For opioid rotation, quick-acting opioids other than morphine are expected to be launched in Japan.

Effectiveness of modified parent training for mothers of children with Pervasive Developmental Disorder on parental confidence and children's behavior.

AIM: This study used parent training (PT), with modifications to smaller groups and shorter schedules (PTSS), for mothers of children with Pervasive Developmental Disorder (PDD). The usefulness of PTSS was evaluated according to the parent's confidence and child's behavior by questionnaire. METHOD: PTSS was used on 14 mothers of 14 children with PDD of preschool to elementary school age, and performed in small groups of 3-4 mothers each. One PTSS course comprised six consecutive sessions and was completed within three months. The sessions consisted mainly of training for parenting skills, understanding the children's inappropriate behaviors, and helping the children adapt to school. The effectiveness of PTSS was assessed by changes in the scores for confidence degree questionnaire for families (CDQ) and the child behavior checklist (CBCL), determined before and after each course. RESULTS: The average CDQ scores increased for 17 of 18 items after completion of the PTSS course in all 14 mothers. The change was statistically significant in five items. Increases in average CDQ scores were also seen in 10 of 18 items assessed in fathers, although none were significant. The CBCL total T-score decreased in 10 of 14 children (71.4%). The remaining four children showed an increased CBCL total T-score. CONCLUSION: These results indicated that PTSS is useful based on changes in the parents' CDQ scores and children's CBCL scores.

Molecular and clinical characterization of cardio-facio-cutaneous (CFC) syndrome: overlapping clinical manifestations with Costello syndrome.

Cardio-facio-cutaneous (CFC) syndrome is a multiple congenital anomaly/mental retardation syndrome characterized by heart defects, a distinctive facial appearance, ectodermal abnormalities and mental retardation. Clinically, it overlaps with both Noonan syndrome and Costello syndrome, which are caused by mutations in two genes, PTPN11 and HRAS, respectively. Recently, we identified mutations in KRAS and BRAF in 19 of 43 individuals with CFC syndrome, suggesting that dysregulation of the RAS/RAF/MEK/ERK pathway is a molecular basis for CFC syndrome. The purpose of this study was to perform comprehensive mutation analysis in 56 patients with CFC syndrome and to investigate genotype-phenotype correlation. We analyzed KRAS, BRAF, and MAP2K1/2 (MEK1/2) in 13 new CFC patients and identified five BRAF and one MAP2K1 mutations in nine patients. We detected one MAP2K1 mutation in three patients and four new MAP2K2 mutations in four patients out of 24 patients without KRAS or BRAF mutations in the previous study [Niihori et al., 2006]. No mutations were identified in MAPK3/1 (ERK1/2) in 21 patients without any mutations. In total, 35 of 56 (62.5%) patients with CFC syndrome had mutations (3 in KRAS, 24 in BRAF, and 8 in MAP2K1/2). No significant differences in clinical manifestations were found among 3 KRAS-positive patients, 16 BRAF-positive patients, and 6 MAP2K1/2-positive patients. Wrinkled palms and soles, hyperpigmentation and joint hyperextension, which have been commonly reported in Costello syndrome but not in CFC syndrome, were observed in 30-40% of the mutation-positive CFC patients, suggesting a significant clinical overlap between these two syndromes.

A novel KCNQ4 one-base deletion in a large pedigree with hearing loss: implication for the genotype-phenotype correlation.

Autosomal-dominant, nonsyndromic hearing impairment is clinically and genetically heterogeneous. We encountered a large Japanese pedigree in which nonsyndromic hearing loss was inherited in an autosomal-dominant fashion. A genome-wide linkage study indicated linkage to the DFNA2 locus on chromosome 1p34. Mutational analysis of KCNQ4 encoding a potassium channel revealed a novel one-base deletion in exon 1, c.211delC, which generated a profoundly truncated protein without transmembrane domains (p.Q71fsX138). Previously, six missense mutations and one 13-base deletion, c.211_223del, had been reported in KCNQ4. Patients with the KCNQ4 missense mutations had younger-onset and more profound hearing loss than patients with the 211_223del mutation. In our current study, 12 individuals with the c.211delC mutation manifested late-onset and pure high-frequency hearing loss. Our results support the genotype-phenotype correlation that the KCNQ4 deletions are associated with later-onset and milder hearing impairment than the missense mutations. The phenotypic difference may be caused by the difference in pathogenic mechanisms: haploinsufficiency in deletions and dominant-negative effect in missense mutations.