SEM1, a homologue of the split hand/split foot malformation candidate gene Dss1, regulates exocytosis and pseudohyphal differentiation in yeast

The exocyst is an essential multiprotein complex mediating polarized secretion in yeast. Here we describe a gene, SEM1, that can multicopy-suppress exocyst mutants sec3-2, sec8-9, sec10-2, and sec15-1. SEM1 is highly conserved among eukaryotic species. Its human homologue, DSS1, has been suggested as a candidate gene for the split hand/split foot malformation disorder. SEM1 is not an essential gene. However, its deletion rescued growth of the temperature-sensitive exocyst mutants sec3-2, sec8-9, sec10-1, and sec15-1 at the restrictive temperature. Cell fractionation showed that Sem1p is mainly cytosolic but also associates with the microsomal fraction. In linear sucrose gradients, Sem1p cosedimented with the exocyst component Sec8p. In diploid cells that normally do not form pseudohyphae (S288C background), deletion of SEM1 triggered pseudohyphal growth. This phenotype was abolished after reintroduction of either SEM1 or the mouse homologue Dss1 into the cells. In diploids that have normal capacity for pseudohyphal growth (Sigma1278b background), deletion of SEM1 enhanced filamentous growth. The functionality of both SEM1 and Dss1 in a differentiation process in yeast suggests that Dss1 indeed could be the gene affected in the split hand/split foot malformation disorder. These results characterize SEM1 as a regulator of both exocyst function and pseudohyphal differentiation and suggest a unique link between these two cellular functions in yeast.     

Split hand/split foot, syndactyly, urinary tract obstruction, radial, diaphragmatic, and neural tube defects: Czeizel-Losonci syndrome?

There has been considerable debate as to the risk of suicide, accidents, and homicide in populations at high risk for HIV infection. The purpose of the present investigation was to determine the incidence of sudden and unexpected deaths in a well-defined cohort of homosexual and bisexual men prospectively studied since 1984. All subjects were enrolled in the Pitt Men's Study, the Pittsburgh, Pennsylvania, component of the Multicenter AIDS Cohort Study. Of this group, 861 were between the ages of 20 and 44, and 35% were seropositive for HIV. There were 70 deaths attributed to AIDS. Five additional deaths were classified as sudden and unexpected, an annual rate of 0.08% (80/100,000). Only one of these was classified by the coroner's office as a suicide; three were due to accidents, and one was a drug overdose of undetermined cause. Only two of the five unexpected deaths were HIV seropositive, and none had the diagnosis of AIDS. The sudden and unexpected death rate in this cohort did not significantly differ from the 0.07% (70/100,000) yearly incidence in the age- and race-matched male population. Thus, in this well-defined male gay cohort, there does not appear to be an increased risk of violent and drug-related deaths in persons at risk for, or with a diagnosis of, AIDS.     

Four sibs with dislocated elbows, bowed tibiae, scoliosis, deafness, cataract, microcephaly, and mental retardation: a new MCA/MR syndrome

We report four sibs with an MCA/MR syndrome whose parents were first cousins. The sibs had mental retardation, microcephaly, hearing problems, cataract, and multiple osseous malformations, such as dislocated elbows, bowed tibiae, and scoliosis. Review of published reports and the use of the London Dysmorphology Database suggest that this family presents a new syndrome.     

FISH analysis of a complex chromosome rearrangement involving nine breakpoints on chromosomes 6, 12, 14 and 16

We report the prenatal diagnosis of an apparently balanced de novo complex chromosome rearrangement (CCR) which involved nine breakpoints on four different chromosomes. Fluorescence in situ hybridization (FISH) and spectral karyotyping (SKY) were performed as an adjunct to G-banding for characterization of the abnormal chromosomes. The 22-week female fetus showed minor dysmorphic features including dolichocephaly, broad fingernails, tibial bowing, clubfoot, thoracolumbar scoliosis and hypoplastic toenails. Autopsy revealed gall-bladder hypoplasia and an atrial septal defect. Chromosome analysis of fetal tissue confirmed the presence of the complex rearrangement.     

Isochromosome 18q in a fetus with congenital megacystis, intra-uterine growth retardation and cloacal dysgenesis sequence

We present the first report of a female fetus with concomitant isochromosome 18q [i(18q)] and cloacal dysgenesis sequence. Prenatal sonographic examination at 15 weeks' gestation showed intra-uterine growth retardation, a normal brain, a normal spine, congenital megacystis and oligohydramnios. The pregnancy was terminated. The abortus displayed dysmorphic features of a high forehead, hypertelorism, a prominent nose with a bulbous tip, median cleft lip and palate, micrognathia, low-set ears, a short neck, a joint contracture at the wrist, prominent heels and pseudo-hermaphroditism. Necropsy confirmed an imperforate anus, megacystis, a phallic structure and cloacal dysgenesis sequence. Postnatal chromosomal investigation proved a pure de novo i(18q). Molecular genetic analysis by polymorphic microsatellite markers confirmed the maternal origin of the aberrant chromosome. The coexistence of cloacal dysgenesis sequence and i(18q) in this case shows a correlation between the disturbance of the caudal developmental field and the chromosomal abnormality with monosomy 18p and trisomy 18q. Our presentation also demonstrates the importance of perinatal cytogenetic analysis in malformed fetuses in order to uncover underlying genetic disorders.     

Refined localization of the asparagine synthetase gene (ASNS) to chromosome 7, region q21.3, and characterization of the somatic cell hybrid line 4AF/106/KO15

We have mapped the asparagine synthetase gene (ASNS) to 7q21.3 by fluorescence in situ hybridization. While this study refined the localization of the gene, it also revealed a rearrangement in a somatic cell hybrid line which was used in previous ASNS mapping. Using additional probes from other regions of human chromosome 7, we showed that this cell line (4AF/106/KO15) contained a rearranged chromosome 7 in which a segment of the long arm was apparently duplicated and inserted into the short arm. Caution should be used therefore when interpreting data obtained from this cell line for gene mapping studies.     

Comparison of the Interplak and manual toothbrushes in a population with mental retardation/developmental disabilities (MR/DD)

A still debated question in the field of the cytokine network in psoriasis is represented by contrasting data reported on the local amount of IL-1 beta amounts, of IL-1 in this dermatosis. In fact previous studies have suggested that there were decreased Il-1 alpha amounts at the lesional level but increased nonfunctional IL-1 beta concentrations as compared to the non-lesional and normal epidermis. However, recent data suggest that IL-1 alpha and, to a lesser extent, IL-1 beta amounts, are both increased and biologically active in the epidermal cell suspension of lesional psoriatic skin as compared to those of normal skin. The data reported in the present paper show that IL-1 alpha levels are decreased in psoriatic lesional extracts of whole skin (mean 2.9 +/- 2 pg/mg) as compared to non-lesional (mean 6.7 +/- 6.2 mg/mg; p = 0.02) or normal skin (mean 13.8 +/- 9.4 pg/mg; p = 0.0002). IL-1 alpha concentrations were also significantly lower in the non-lesional skin than in normal skin (p = 0.02). In contrast, the IL-1 beta levels (mean 1.2 +/- 0.74 pg/mg were higher in the lesional samples than in the non-lesional ones (mean 0.5 +/- 0.4 pg/mg; p = 0.0004) or in normal skin (mean 0.4 +/- 0.2 pg/mg; p = 0.004). No differences in IL-1 beta levels were observed between non-lesional and normal skin (p = 0.3). In addition both IL-1 alpha and IL-1 beta are directly correlated with the disease severity and each other. Our data, extending the Il-1 determination to the whole skin, seem to confirm the previously reported findings at the epidermis level and provide new light on possible interpretation of literature discrepancies.     

Partial duplication of 3q and distal deletion of 11q in a stillbirth with an omphalocele containing the liver, short limbs, and intrauterine growth retardation

We describe a female stillbirth with duplication of 3q21-->qter and deletion of 11q23-->qter resulting from an unbalanced segregation of a maternal t(3;11) reciprocal translocation. The proband had some of the clinical features consistent with those seen in patients with dup(3q) syndrome or distal del(11q) syndrome. Prenatal sonographic examination showed short limbs, intrauterine growth retardation, and an omphalocele containing the liver.     

X-linked hydrocephalus, with aqueductal stenosis, mental retardation, and adduction-flexion deformity of the thumbs. Report of a family

A new family is reported of a Bickers-Adams-Edwards syndrome. This family has been studied up to three generations. Two female carriers are known. Among the six male children who are affected, four are severely mentally retarded, have spasticity of the legs, and survived with a mild macrocephaly, and two show a more severe and rapid progression of head enlargement. A partial aqueductal stenosis, with remarkable ventricular dilatation, has been demonstrated by pneumoence-phalography in three boys. A deformity of the thumbs links these six children together. One of them has been treated by a ventriculoperitoneal shunt, when 18 months old, without any improvement in the neurological condition. The mental deficiency is much more severe than could be expected from the degree of hydrocephalus, at least as estimated clinically by the macrocephaly. Hydrocephalus is precocious, and the ventricular dilatation very advanced when seen by PEG studies. Recognition of the female carriers is not possible.     

Acute myelogenous leukemia with monosomy 7, inv(3) (q21q26), involving activated EVI 1 gene occurring after a complete remission of lymphoblastic lymphoma: a case report

A 42-year-old female with a mediastinal tumor and massive pleural effusion ws admitted to our hospital in June 1993. Biopsy revealed lymphoblastic lymphoma. She had no evidence of distant metastasis except pleural effusion. Bone marrow examination revealed a normal karyotype (46, XY). The patient had been progression-free for more than 1 year after achieving complete remission by induction, consolidation and maintenance therapy according to the standard chemotherapy and involved-field radiation for lymphoblastic lymphoma. From May 1996 progressive leukopenia and thrombocytopenia developed. The diagnosis of refractory anemia with excess of blasts (RAEB) was made. Subsequently, in November 1996, she developed acute myelogenous leukemia (AML), M4 type by FAB classification. The karyotype of MDS and AML clones involved inversion (3) (q21q26) and monosomy 7. The EVI 1 gene was examined and was proved to be rearranged and activated. This may be the first case among the therapy-related cases of MDS/AML reported whose karyotypes were followed and in which the mRNA expression of EVI 1 gene involved was directly proved in the leukemogenesis process of chemotherapy-induced secondary MDS and AML.     

The inv dup(15) syndrome: a clinically recognizable syndrome with altered behavior, mental retardation, and epilepsy

The most common of the heterogeneous group of the extra structurally abnormal chromosomes (ESACs) is the inv dup(15), whose presence results in tetrasomy 15p and partial tetrasomy 15q. Inv dup(15), containing the Prader-Willi/Angelman syndrome (PWS/AS) region, are constantly associated with phenotypic abnormalities and mental retardation. We report on four additional patients with inv dup(15), whose behavioral pattern, and neurologic and physical findings further delineate the phenotype of this neurogenetic syndrome. We also provide FISH analyses on chromosomes of the observed ESACs and discuss the role of a number of genes located within the tetrasomic region.     

De novo balanced 5;21 translocation in a child with acrobrachycephaly, ventriculomegaly, pulmonary stenosis, ectopic anus and mental retardation

An apparently balanced de novo reciprocal translocation t(5;21) (q13;q22) was demonstrated in a girl with acrobrachycephaly, ventriculomegaly, pulmonary stenosis and anal malformation. The possible relationships between her karyotype and malformations are discussed.     

Association of Duane anomaly with mental retardation, cardiac and urinary tract abnormalities: a new autosomal recessive condition?

The authors report on a child in which the occurrence of cardiac defect, urinary tract anomaly, and Duane anomaly was associated with mental retardation. The parents were first cousins. The index case was a 3-year-old girl referred for mental retardation. Auricular septal defect was diagnosed at birth. She was surgically treated for bilateral vesico-ureteral reflux at 2 years of age. At examination, she had a mild facial dysmorphism, microcephaly, spastic paraplegia and Duane anomaly. The Duane anomaly may occur in association with various partly overlapping syndromes that may be part of the same clinical spectrum, as the cervico-oculo-acoustic syndrome, the cat eye syndrome and syndromes inherited in an autosomal dominant fashion: the acro-reno-ocular syndrome and the Okihiro syndrome. Their patient seems to have a different condition from all of these previously reported syndromes associated with the Duane anomaly. Their suggest that this condition is best described as a new syndrome.     

Multilocus linkage identifies two new loci for a mendelian form of stroke, cerebral cavernous malformation, at 7p15-13 and 3q25.2-27

Cerebral cavernous malformation (CCM) is a Mendelian model of stroke, characterized by focal abnormalities in small intracranial blood vessels leading to hemorrhage and consequent strokes and/or seizures. A significant fraction of cases is inherited as an autosomal dominant trait with incomplete penetrance. Among Hispanic Americans, virtually all CCM is attributable to a founder mutation localized to 7q ( CCM1 ). Recent analysis of non-Hispanic Caucasian kindreds, however, has excluded linkage to 7q in some, indicating at least one additional CCM locus. We now report analysis of linkage in 20 non-Hispanic Caucasian kindreds with familial CCM. In addition to linkage to CCM1, analysis of linkage demonstrates linkage to two new loci, CCM2 at 7p13-15 and CCM3 at 3q25.2-27. Multilocus analysis yields a maximum lod score of 14.11, with 40% of kindreds linked to CCM1, 20% linked to CCM2 and 40% linked to CCM3, with highly significant evidence for linkage to three loci (linkage to three loci supported with an odds ratio of 2.6 x 10(5):1 over linkage to two loci and 1.6 x 10(9):1 over linkage to one locus). Multipoint analysis among families with high posterior probabilities of linkage to each locus refines the locations of CCM2 and CCM3 to approximately 22 cM intervals. Linkage to these three loci can account for inheritance of CCM in all kindreds studied. Significant locus-specific differences in penetrance are identified. These findings have implications for genetic testing of this disorder and represent an important step toward identification of the molecular basis of this disease.     

A cytogenetic deletion, del(17)(q11.22q21.1), in a patient with sporadic neurofibromatosis type 1 (NF1) associated with dysmorphism and developmental delay

Pure primary ovarian carcinoid tumors are uncommon and only 21 cases have been recorded in the literature. In the past 15 years, we have seen two cases. One was a strumal carcinoid and the other, the case presented here, was a primary ovarian carcinoid tumor arising from the left ovary of a 25-year-old woman who had no carcinoid syndrome. The tumor was made up of pure carcinoid tumor without other teratomatous elements. On light microscopy the neoplasm, composed of uniform tumor cells, was arranged in solid nests or a trabecular pattern. The differential diagnosis included granulosa cell tumor. However, the strongly argyrophilic, chromogranin staining and ultrastructural presence of neurosecretory granules confirmed the diagnosis of primary ovarian carcinoid tumor. After a careful survey of the contralateral ovary and the gastrointestinal tract, the patient underwent a left oophorectomy. Her postoperative course was uneventful. The literature and the pathologic findings are reviewed and discussed, along with the differential diagnosis and treatment of primary ovarian carcinoid tumor.     

Hepatosplenic gamma/delta T-cell lymphoma: a report of two cases in immunocompromised patients, associated with isochromosome 7q

Two cases of peripheral T-cell lymphoma, characterized by hepatosplenic presentation and gamma/delta T-cell receptor phenotype on malignant cells, are reported. Little is known about the chromosomal changes in these peculiar lymphomas. We report the cytogenetic analysis of these two patients. Isochromosome 7q and trisomy 8 were observed. These abnormalities were reported previously in five cases of gamma/delta T-cell lymphoma. These two patients had lymphomatous infiltration of the spleen, liver, bone marrow, and (in one case) lymph nodes. These abnormalities occurred in immunocompromised patients (i.e., immunosuppressive therapy for kidney transplantation and chemotherapy for Hodgkin's disease), without Epstein-Barr virus infection stigmata in tumor cells.     

De novo unbalanced translocation resulting in monosomy for proximal 14q and distal 4p in a fetus with intrauterine growth retardation, Wolf-Hirschhorn syndrome, hypertrophic cardiomyopathy, and partial hemihypoplasia

We present the perinatal findings of a fetus with a de novo unbalanced chromosome translocation that resulted in monosomy for proximal 14q and monosomy for distal 4p. Prenatal sonographic examination at 27 weeks of gestation showed intrauterine growth retardation, microcephaly, cardiomegaly with arrhythmia, and asymmetry of the upper limbs. Genetic amniocentesis showed an abnormal karyotype of 45,XX,der(4)t(4;14)(p16.3;q12),-14. Linkage analysis of the family confirmed the maternal origin of the deletions. Molecular refinement of the deletion breakpoints indicated that the breakpoints at 4p16.3 and 14q12 were located between loci D4S403 (present) and D4S394 (absent), and between loci D14S252 (present) and D14S64 (absent), respectively. Necropsy showed dysmorphic features compatible with Wolf-Hirschhorn syndrome, hypertrophic cardiomyopathy, partial hemihypoplasia, and a normal brain without evidence of holoprosencephaly. Our case adds to the list of clinical phenotypes associated with the proximal regions of 14q.     

Fusion of the MLL gene with two different genes, AF-6 and AF-5alpha, by a complex translocation involving chromosomes 5, 6, 8 and 11 in infant leukemia

We analysed a complex translocation involving chromosomes 5, 6, 8 and 11 in a case of infant leukemia. Molecular analysis of the MLL gene revealed that MLL was fused with two different genes, AF-6 on chromosome 6q27 and AF-5alpha. AF-5alpha, the 11th partner gene fused with MLL, is a novel gene mapped to chromosome 5q12, which encodes a 31 kDa protein of 269 amino acids and contains a possible nuclear targeting sequence, a potential leucine zipper dimerization motif and an alpha-helical coiled-coil domain. In situ hybridization and molecular cloning analyses demonstrated that two different types of chromosomal recombination had occurred in the cells. One was a three-way translocation among chromosomes 6, 8 and 11, and the other was an insertion of a chromosome 5-derived segment into the breakpoint of chromosomes 8 and 11. Accordingly, the karyotype was defined as del(5)(q11.2q12), der(6)t(6;8) (q27;q11.2), der(8)(8pter-->8q11.2::5q11.2-->5q12::11q23-->++ +11qter), der(11)t(6;11) (q27;q23). Thus, the MLL gene created two different fusion mRNAs, since the chromosome 11 split into two different chromosomes 5 and 6. This is the first report demonstrating fusion of the MLL gene with two different genes by a complex translocation.     

Clinical features and mental development of a child with a prenatally identified 45,XX,der(5)t(5;18) (p15;q11.2),-18 karyotype

We present the clinical features and growth and development of a child with a 45,XX,der(5)t(5;18) (p15;q11.2),-18 karyotype. She had microcephaly, prominent, posteriorly rotated ears, short palpebral fissures with an upward slant, a wide nasal bridge, a thin upper lip, and a short neck. In addition, she had complex congenital heart disease. Although there has been delay in growth and development, she has shown progress in both areas.