1/300. ataxia, ocular telangiectasia, chromosome instability, and Langerhans cell histiocytosis in a patient with an unknown breakage syndrome.An 8 year old boy who had Langerhans cell histiocytosis when he was 15 months old showed psychomotor regression from the age of 2 years. microcephaly, severe growth deficiency, and ocular telangiectasia were also evident. Magnetic nuclear resonance imaging showed cerebellar atrophy. Alphafetoprotein was increased. Chromosome instability after x irradiation and rearrangements involving chromosome 7 were found. Molecular study failed to show mutations involving the ataxia-telangiectasia gene. This patient has a clinical picture which is difficult to relate to a known breakage syndrome. Also, the relationship between the clinical phenotype and histiocytosis is unclear.- - - - - - - - - - ranking = 1keywords = chromosome (Clic here for more details about this article) |
2/300. Kenny-Caffey syndrome: an Arab variant?We describe 2 unrelated Bedouin girls who met the criteria for the diagnosis of Kenny-Caffey syndrome. The girls had some unusual features--microcephaly and psychomotor retardation--that distinguish the Kenny-Caffey syndrome profile in Arab children from the classical Kenny-Caffey syndrome phenotype characterized by macrocephaly and normal intelligence. The 2 girls did not harbor the 22q11 microdeletion (the hallmark of the DiGeorge cluster of diseases) that we previously reported in another Bedouin family with the Kenny-Caffey syndrome (Sabry et al. J Med Genet 1998: 35(1): 31-36). This indicates considerable genetic heterogeneity for this syndrome. We also review previously reported 44 Arab/Bedouin patients with the same profile of hypoparathyroidism, short stature, seizures, mental retardation and microcephaly. Our results suggest that these patients represent an Arab variant of Kenny-Caffey syndrome with characteristic microcephaly and psychomotor retardation. We suggest that all patients with Kenny-Caffey syndrome should be investigated for the 22q11 microdeletion. Other possible genetic causes for the Kenny-Caffey syndrome or its Arab variant include chromosome 10p abnormalities.- - - - - - - - - - ranking = 0.2keywords = chromosome (Clic here for more details about this article) |
3/300. dyskeratosis congenita: an autosomal recessive variant.We describe a woman with dyskeratosis congenita (DKC), microcephaly, and a purple discoloration of the tongue. The latter findings are not commonly described in males with DKC, have been reported in another female patient with this condition, and may represent the phenotype of an autosomal recessive entity of DKC. Results of x chromosome inactivation studies did not support X-linked DKC in our family. The additional findings of an affected brother and parental consanguinity support the hypothesis of autosomal recessive inheritance.- - - - - - - - - - ranking = 0.2keywords = chromosome (Clic here for more details about this article) |
4/300. syndrome of microcephaly, Dandy-Walker malformation, and wilms tumor caused by mosaic variegated aneuploidy with premature centromere division (PCD): report of a new case and review of the literature.We report a male infant with multiple congenital anomalies and mosaic variegated aneuploidy; a rare cytogenetic abnormality characterized by mosaicism for several different aneuploidies involving many different chromosomes. He had prenatal-onset growth retardation, microcephaly, dysmorphic face, seizures, hypotonia, feeding difficulty, and developmental delay. In addition, he developed bilateral Wilms tumors. Neuroradiological examination revealed Dandy-Walker malformation and hypoplasia of the cerebral hemisphere and pons. cytogenetic analysis revealed various multiple numerical aneuploidies in blood lymphocytes, fibroblasts, and bone marrow cells, together with premature centromere division (PCD). Peripheral blood chromosome analysis from his parents also showed PCD, but no aneuploid cells. The clinical phenotype and multiple aneuploidies of the patient may be a consequence of the homozygous PCD trait inherited from his parents. Comparison with previously reported cases of multiple aneuploidy suggests that mosaic variegated aneuploidy with PCD may be a clinically recognizable syndrome with major phenotypes being mental retardation, microcephaly, structural brain anomalies (including Dandy-Walker malformation), and possible cancer predisposition.- - - - - - - - - - ranking = 0.4keywords = chromosome (Clic here for more details about this article) |
5/300. Partial duplication of 4q12q13 leads to a mild phenotype.We report on the second case of duplication (4)(q12q13) with microcephaly, mental retardation, and minor facial anomalies. Duplications involving the distal region of chromosome 4q are well described and share common clinical findings. However, phenotypic abnormalities of duplications of the proximal portion of chromosome 4q are relatively unknown. A comparison of the clinical manifestations of our patient and the single published case suggests that the phenotype of this proximal 4q duplication is relatively mild. This study emphasizes the need to perform chromosome analysis in similar mildly affected/nonspecific cases.- - - - - - - - - - ranking = 0.6keywords = chromosome (Clic here for more details about this article) |
6/300. Aicardi-Goutieres syndrome: a genetic microangiopathy?Aicardi-Goutieres syndrome (AGS) (McKusick 225750) is an autosomal recessive disease with onset in the 1st year of life, resulting in progressive microcephaly, calcification of cerebral white matter, thalamus and basal ganglia, generalized cerebral demyelination and a chronic low-grade CSF lymphocytosis, without evidence of infection. We report the autopsy of a patient who died with this disorder at the age of 17 years. Findings were severe microencephaly, diffuse but inhomogeneous cerebral white matter loss with associated astrocytosis, calcific deposits in the white matter, thalami and basal ganglia. neocortex and cerebellar cortex were affected by wedge-shaped microinfarctions. Small vessels showed calcification in the media, adventitia and perivascular spaces. These findings are similar to some previous publications that in retrospect may have been AGS, but this is the first reported cerebral microangiopathy in which the diagnosis AGS was made during lifetime. This report provides evidence that microangiopathy plays a significant role in the pathogenesis of AGS.- - - - - - - - - - ranking = 0.0047722189248991keywords = ring (Clic here for more details about this article) |
7/300. Chromosome duplications and deletions and their mechanisms of origin.Duplications and deletions of the same gene loci or chromosome regions are known to produce different clinical manifestations and are significant factors in human morbidity and mortality. Extensive cytogenetic and molecular cytogenetic studies with cosmid and YAC probes in two patients with unique mosaicism for reciprocal duplication-deletion allowed us to further understand the origin of these abnormalities. The first patient's mosaic karyotype was 46,XX, inv dup(11) (q23q13)/46,XX,del(11)(q13q23). The second patient had a 46,XY,dup(7)(p11.2p13)/46,XY,del(7)(p11.2p13)/46,XY karyotype. fluorescence in situ hybridization studies on the first patient placed the two breakpoints near the folate-sensitive fragile sites FRA11A and FRA11B. The presence of repeated sequences responsible for these fragile sites may have been involved in the patient's duplication-deletion. Our investigation leads us to conclude that, in addition to known mechanisms (such as unequal crossovers between homologs, unequal sister chromatid exchanges, excision of intrachromatid loops, and meiotic recombination within a single chromatid), duplication-deletion can also arise by the formation of an overlying loop followed by an uneven crossover at the level of the dna strand.- - - - - - - - - - ranking = 0.2keywords = chromosome (Clic here for more details about this article) |
8/300. A de novo complex chromosomal rearrangement with nine breakpoints characterized by FISH in a boy with mild mental retardation, developmental delay, short stature and microcephaly.A de novo complex chromosome rearrangement (CCR) involving chromosomes 1, 6, 7, 15 and Y was detected in a boy with mental retardation, short stature, and microcephaly. fluorescence in situ hybridisation (FISH) with whole chromosome painting libraries, band-specific cosmids and telomeric probes was essential for the characterisation of the rearrangement. The CCR was shown to be the result of at least nine chromosomal breaks and involved the alternating insertion of two segments of the short arm of chromosome 1 and two segments of the long arm of chromosome 6 into a novel derived chromosome 7. A non-reciprocal translocation between the distal short arm of the same chromosome 7 and the distal long arm of the y chromosome was also found, together with a paracentric inversion of the long arm of chromosome 15. The only detectable imbalance was a deletion of the heterochromatic Yq telomeric region. FISH investigations in this case have revealed an additional complexity in this CCR, which has implications for reproductive risk assessment and genetic counselling.- - - - - - - - - - ranking = 1.8keywords = chromosome (Clic here for more details about this article) |
9/300. Another case of achalasia-microcephaly syndrome.The first German patient with achalasia-microcephaly syndrome is described. The mother was exposed to the anti-malarial drug mefloquine during the first 8 weeks of pregnancy.- - - - - - - - - - ranking = 0.0047722189248991keywords = ring (Clic here for more details about this article) |
10/300. 46, XY, del (3) (pter-->p25) syndrome: further delineation of the clinical phenotype.A boy with monosomy for the distal part of the short arm of chromosome 3 is described. The clinical features this patient has in common with the previously reported cases include pre- and post-natal growth delay, microcephaly, craniofacial dysmorphism and mental retardation. In addition, minor abnormalities not previously reported were observed, such as snapping thumbs, dorsiflected big toes, connecting anterior and posterior fontanelles at birth, nasolacrimal duct stenosis and double urethral meatus.Conclusion These five new clinical findings may help in further delineation of the syndrome and allow its early recognition. A complete revision of clinical findings published in literature is reported.- - - - - - - - - - ranking = 0.2keywords = chromosome (Clic here for more details about this article) |
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