Severe fluoropyrimidine-related toxicity: clinical implications of DPYD analysis and UH2/U ratio evaluation.

The fluoropyrimidines are commonly used in chemotherapeutic cancer medicine, but many patients still experience severe adverse side effects from these drugs. We observed a severe toxicity in a 50-year-old woman treated with capecitabine and docetaxel for a metastatic breast cancer. Since dihydropyrimidine dehydrogenase (DPD) is the main candidate for pharmacogenetic studies on 5-FU toxicity, the entire coding sequence and exon-flanking intronic regions of the DPYD gene were sequenced in the patient. None of the previously described deleterious variants were detected. Also, the haplotype-based analysis failed to reveal DPYD variations associated with 5-FU toxicity. We also evaluated the UH2/U ratio in plasma as an index of 5-FU pharmacokinetics. The UH2/U value did not demonstrate low DPD activity in the patient. We discuss the advantages and limitations of this approach, particularly concerning the clinical applications of 5-FU pharmacogenetics in the family setting.

Phenotype of five cases of prenatally diagnosed campomelic dysplasia harboring novel mutations of the SOX9 gene.

OBJECTIVES: Campomelic dysplasia is a rare congenital skeletal disorder characterized by bowing of the long bones and a variety of other skeletal and extraskeletal defects, many of which can now be identified prenatally using advanced ultrasound equipment. The disorder is caused by mutations in SRY-box 9 (SOX9), a gene that is abundantly expressed in chondrocytes as well as in other tissues. However, the correlation between genotype and phenotype is still unclear. We report five cases of prenatally detected campomelic dysplasia in which the diagnosis was confirmed by molecular analysis. METHODS: Ultrasound examinations were performed between 12 and 32 weeks. Standard fetal biometric measurements were obtained. Fetal sex was determined sonographically and confirmed by chromosomal analysis. Genomic DNA was obtained in four cases before termination of pregnancy from chorionic villi or amniocytes and in one case postnatally from peripheral blood. RESULTS: Skeletal dysplasia, most often limb shortening and bowed femora, was observed in one case in the first trimester, in three cases in the second trimester and in one case, presenting late for antenatal care, in the third trimester. Four of the pregnancies were terminated and one was carried to term. Postmortem/postnatal physical and radiographic examinations confirmed the presence of anomalies characteristic of campomelic dysplasia. A de novo mutation in the SOX9 gene was detected in all four cases that underwent termination. The father of the proband in the case that went to term was a carrier of a somatic mosaic mutation without clinical or radiographic signs of campomelic dysplasia. CONCLUSIONS: It is likely that the integrated expertise of ultrasonographers, obstetricians, pediatricians and clinical geneticists will markedly improve the likelihood of accurate prenatal clinical diagnoses of campomelic dysplasia. This will, in turn, encourage more specific molecular testing and facilitate comprehensive genetic counseling.

Joubert syndrome with bilateral polymicrogyria: clinical and neuropathological findings in two brothers.

Joubert syndrome (JS) is characterized by hypotonia, ataxia, developmental delay, and a typical neuroimaging finding, the so-called "molar tooth sign" (MTS). The association of MTS and polymicrogyria (PMG) has been reported as a distinct JS-related disorder (JSRD). So far, five patients have been reported with this phenotype, only two of them being siblings. We report on one additional family, describing a living child with JS and PMG, and the corresponding neuropathological picture in the aborted brother. No mutations were detected in the AHI1 gene, the only so far associated with the JS + PMG phenotype. Moreover, linkage analysis allowed excluding all known gene loci, suggesting further genetic heterogeneity.

Mowat-Wilson syndrome: facial phenotype changing with age: study of 19 Italian patients and review of the literature.

Mowat-Wilson syndrome (MWS; OMIM #235730) is a genetic condition caused by heterozygous mutations or deletions of the ZEB2 gene, and characterized by typical face, moderate-to-severe mental retardation, epilepsy, Hirschsprung disease, and multiple congenital anomalies, including genital anomalies (particularly hypospadias in males), congenital heart defects, agenesis of the corpus callosum, and eye defects. Since the first delineation by Mowat et al. [Mowat et al. (1998); J Med Genet 35:617-623], approximately 179 patients with ZEB2 mutations, deletions or cytogenetic abnormalities have been reported primarily from Europe, Australia and the United States. Genetic defects include chromosome 2q21-q23 microdeletions (or different chromosome rearrangements) in few patients, and ZEB2 mutations in most. We report on clinical and genetic data from 19 Italian patients, diagnosed within the last 5 years, including six previously published, and compare them with patients already reported. The main purpose of this review is to underline a highly consistent phenotype and to highlight the phenotypic evolution occurring with age, particularly of the facial characteristics. The prevalence of MWS is likely to be underestimated. Knowledge of the phenotypic spectrum of MWS and of its changing phenotype with age can improve the detection rate of this condition.

A familial case of achondrogenesis type II caused by a dominant COL2A1 mutation and "patchy" expression in the mosaic father.

Achondrogenesis type II (ACG2) is the most severe disorder that can be produced by dominant mutations in COL2A1. We report on four pregnancies of an apparently healthy, nonconsanguineous young couple. The father had scoliosis as a child, and has slight body disproportion with short trunk. The first child was born at 32 weeks and died neonatally. In the second pregnancy, short limbs and fetal hygroma were noted on ultrasound at 17 weeks' gestation. Similar findings were observed in the third fetus. Clinical, radiological, and histological evaluation of the fetuses after termination of the pregnancies showed findings consistent with ACG2. Molecular analysis of genomic DNA extracted from amniotic cells of the second and third fetuses revealed heterozygosity for a 10370G > T missense mutation (G346V) in the COL2A1 gene. This mutation was also found in the father, as a mosaic. The couple had a fourth pregnancy, and at 11 weeks fetal hydrops with a septated cystic hygroma were obvious. DNA from CVS demonstrated the same COL2A1 mutation.

Mutations in PHF8 are associated with X linked mental retardation and cleft lip/cleft palate.

Truncating mutations were found in the PHF8 gene (encoding the PHD finger protein 8) in two unrelated families with X linked mental retardation (XLMR) associated with cleft lip/palate (MIM 300263). Expression studies showed that this gene is ubiquitously transcribed, with strong expression of the mouse orthologue Phf8 in embryonic and adult brain structures. The coded PHF8 protein harbours two functional domains, a PHD finger and a JmjC (Jumonji-like C terminus) domain, implicating it in transcriptional regulation and chromatin remodelling. The association of XLMR and cleft lip/palate in these patients with mutations in PHF8 suggests an important function of PHF8 in midline formation and in the development of cognitive abilities, and links this gene to XLMR associated with cleft lip/palate. Further studies will explore the specific mechanisms whereby PHF8 alterations lead to mental retardation and midline defects.

Multiple mechanisms are implicated in the generation of 5q35 microdeletions in Sotos syndrome.

BACKGROUND: Sotos syndrome is characterised by learning difficulties, overgrowth, and a typical facial appearance. Microdeletions at 5q35.3, encompassing NSD1, are responsible for approximately 10% of non-Japanese cases of Sotos. In contrast, a recurrent approximately 2 Mb microdeletion has been reported as responsible for approximately 50% of Japanese cases of Sotos. METHODS: We screened 471 cases for NSD1 mutations and deletions and identified 23 with 5q35 microdeletions. We investigated the deletion size, parent of origin, and mechanism of generation in these and a further 10 cases identified from published reports. We used "in silico" analyses to investigate whether repetitive elements that could generate microdeletions flank NSD1. RESULTS: Three repetitive elements flanking NSD1, designated REPcen, REPmid, and REPtel, were identified. Up to 18 cases may have the same sized deletion, but at least eight unique deletion sizes were identified, ranging from 0.4 to 5 Mb. In most instances, the microdeletion arose through interchromosomal rearrangements of the paternally inherited chromosome. CONCLUSIONS: Frequency, size, and mechanism of generation of 5q35 microdeletions differ between Japanese and non-Japanese cases of Sotos. Our microdeletions were identified from a large case series with a broad range of phenotypes, suggesting that sample selection variability is unlikely as a sole explanation for these differences and that variation in genomic architecture might be a contributory factor. Non-allelic homologous recombination between REPcen and REPtel may have generated up to 18 microdeletion cases in our series. However, at least 15 cannot be mediated by these repeats, including at least seven deletions of different sizes, implicating multiple mechanisms in the generation of 5q35 microdeletions.

Nevoid Basal Cell Carcinoma Syndrome in infants: improving diagnosis.

BACKGROUND: Diagnosis of Nevoid Basal Cell Carcinoma Syndrome (NBCCS) in infants may pose significant challenges to clinicians owing to its variable expressivity and age-related manifestations. METHODS: We report two paediatric cases of NBCCS who presented initially with a non-specific phenotype. RESULTS: In case 1, a diagnosis of NBCCS was possible only after the father was interviewed and found to present with two major criteria for the disease. Subsequent molecular testing confirmed the diagnosis. In case 2, molecular testing of the infant and his father had diagnostic value as neither satisfied fully the current diagnostic criteria for NBCCS. CONCLUSIONS: Presence of the few clinical manifestations of NBCCS that appear in infants, typically congenital malformations and skeletal abnormalities, should prompt clinicians to conduct in-person interviews with both parents. In general, paediatricians should refer both parents of infants who are suspected of having an inherited condition to clinical geneticists for expert examination, given the potential unreliability of reported medical history.

Molecular characterization of Italian nevoid basal cell carcinoma syndrome patients.

Mutations in the PTCH gene, the human homolog of the Drosophila patched gene, have been found to lead to the autosomal dominant disorder termed Nevoid Basal Cell Carcinoma Syndrome (NBCCS, also called Gorlin Syndrome). Patients display an array of developmental anomalies and are prone to develop a variety of tumors, with multiple Basal Cell Carcinomas occurring frequently. We provide here the results of molecular testing of a set of Italian Nevoid Basal Cell Carcinoma Syndrome patients. Twelve familial patients belonging to 7 kindreds and 5 unaffected family members, 6 non-familial patients and an additional set of 7 patients with multiple Basal Cell Carcinoma but no other criteria for the disease were examined for mutations in the PTCH gene. All of the Nevoid Basal Cell Carcinoma Syndrome patients were found to carry variants of the PTCH gene. We detected nine novel mutations (1 of which occurring twice): 1 missense mutation (c.1436T>G [p.L479R]), 1 nonsense mutation (c.1138G>T [p.E380X]), 6 frameshift mutations (c.323_324ins2, c.2011_2012dup, c.2535_2536dup, c.2577_2583del, c.3000_3005del, c.3050_3051del), 1 novel splicing variant (c.6552A>T) and 3 mutations that have been previously reported (c.3168+5G>A, c.1526G>T [p.G509V], and c.3499G>A [p.G1167R]). None of the patients with multiple Basal Cell Carcinoma but no other criteria for the syndrome, carried germline coding region mutations.

Cerebro-fronto-facial syndrome: report of a further case.

Cerebro-fronto-facial syndrome had only recently been described in 2001. We present a boy who has dysmorphic features similar to the case described by Der Kaloustian et al. (2001) and propose that he represents a further case of this syndrome.

Crisponi syndrome: report of a further patient.

Crisponi syndrome was described in the original paper in 17 patients form 12 families [Crisponi, 1996: Am J Med Genet 62:365-371]. It is characterised by episodes of muscle contraction in response to external stimuli and intermittent hypethermia with neonatal onset. The disease is often lethal in the first infancy. We describe a patient with the same unusual phenotype.

Cryptic 1p36.3/6q25.2 translocation in three generations ascertained through a foetus with IUGR and cerebral malformations.

Here we describe a foetus with intrauterine growth retardation (IUGR), cerebral malformations and a 46,XY,der(1),t(1;6)(p36.3;q25.2) karyotype owing to a familial cryptic translocation segregating in three generations. A balanced translocation was present in the mother, the maternal uncle, the aunt and the grandmother. A female first cousin with dysmorphisms, hydrocephalus and mental retardation was a carrier of a partial trisomy 1p and a partial monosomy 6q. Multiple miscarriages were present in the family pedigree. Parents of the foetus had three other pregnancies: a male with a balanced translocation, and two foetuses with 1p36.3-pter monosomy and 6q25.2-qter trisomy.

Severe lymphedema, intestinal lymphangiectasia, seizures and mild mental retardation: further case of Hennekam syndrome with a severe phenotype.

We report on an Italian patient affected by severe lymphedema of lower limbs, genitalia and face, intestinal lymphangiectasia, seizures, and moderate mental retardation. He has a flat face, flat nasal bridge, and hypertelorism. We propose that he presents with a severe form of Hennekam syndrome.

Liver iron accumulation in chronic hepatitis C patients without HFE mutations: relationships with histological damage, viral load and genotype and alpha-glutathione S-transferase levels.

BACKGROUND: Host and viral factors have been suggested as possible causative factors for the presence of liver iron accumulation in chronic hepatitis C. However, there is no agreement regarding the influence of liver iron accumulation on the biochemical and histological severity of chronic hepatitis C. Moreover, data concerning the relationships between both viral load and genotype and liver iron accumulation are scanty. AIMS: To evaluate the biochemical, histological and virological assessment of a group of chronic hepatitis C patients without risk factors for iron overload, on the basis of the presence, degree and distribution of liver iron accumulation. METHODS: Fifty-three chronic hepatitis C patients (34 men, 19 women; age 44 +/- 11 years) with no risk factors for liver iron accumulation and showing no HFE mutations were chosen from a broader cohort of chronic hepatitis C patients. The presence, degree and distribution of liver iron accumulation were assessed using Deugnier's score. Relationships between the presence of liver iron accumulation and grading and staging were carried out separately. Hepatitis C virus RNA serum levels and viral genotype were compared in patients with or without liver iron accumulation. Alpha glutathione S-transferase serum levels were assessed in all patients. RESULTS: Overall, liver iron accumulation was mild and was present in 19 patients (36%). It was associated with male gender (P = 0.0358), and was reflected by high serum iron levels (P = 0.001) and high ferritin levels (P < 0.0001). Hepatitis C virus RNA levels and genotype were not associated with the presence of liver iron accumulation. In multivariate analysis, ferritin was the only variable significantly associated with liver iron accumulation (P < 0.0001). Grading was higher in patients with liver iron accumulation regardless of the site of iron deposition. Fibrosis was present in all patients with iron overload; these patients were more frequently cirrhotic. Moreover, patients with mesenchymal or mixed deposition had higher staging than patients with hepatocytic or no iron deposition. This feature was reflected by higher alpha-glutathione S-transferase levels. CONCLUSIONS: Liver iron accumulation is mild in chronic hepatitis C patients without HFE mutations and is mainly reflected by serum ferritin levels. Viral characteristics do not seem to play a role in iron deposition. Liver iron accumulation is associated with higher grading, advanced fibrosis and cirrhosis. Moreover, higher staging is associated with mesenchymal or mixed iron deposition. In these patients, higher alpha-glutathione S-transferase levels seem to reflect more complex damage.