1/50. A microdeletion syndrome due to a 3-Mb deletion on 19q13.2--diamond-Blackfan anemia associated with macrocephaly, hypotonia, and psychomotor retardation.We report on a boy with congenital pure red blood cell aplasia [diamond Blackfan anemia (DBA)] and severe congenital hypotonia, macrocephaly, hypertelorism, a broad and tall forehead, medial epicanthus, and facial hypotonia with mouth-breathing and drooling, an affable and out-going personality, and a general psychomotor retardation. These features show similarity to the phenotype of the X-linked FG syndrome. DBA was diagnosed at the age of 4 months, and the boy underwent treatment with transfusion and with prednisolone. He had a normal 46, XY karyotype, but fluorescence in situ hybridization (FISH) analysis to metaphase chromosomes revealed a 3-Mb deletion on 19q13.2. This chromosomal region has previously been linked to the DBA phenotype and one 19q13 microdeletion has been identified in a patient with DBA. This deletion coincides with the deletion reported here. We suggest that the complex phenotype of our patient, including both DBA and the associated features, represent a microdeletion syndrome.- - - - - - - - - - ranking = 1keywords = chromosome (Clic here for more details about this article) |
2/50. holoprosencephaly, hypertelorism, and ectrodactyly in a boy with an apparently balanced de novo t(2;4) (q14.2;q35).A holoprosencephaly, hypertelorism, and ectrodactyly syndrome (HHES) was described in three previous cases in whom chromosomes were apparently normal. We report on a 3-year-old boy with HHES and a de novo apparently balanced t(2;4)(q14.2;q35) confirmed by fluorescent in situ hybridization. He had severe growth and mental retardation, lobar holoprosencephaly, hypertelorism, microphthalmos, and iris, choroid, and retina colobomata. Less-severe facial involvement correlates with the semilobar type of holoprosencephaly; limb defects consisted of foot ectrodactyly and syndactyly. All previous HHES cases were sporadic and of unknown cause. A cryptic imbalance secondary to the translocation (2;4) in our patient may explain the phenotype.- - - - - - - - - - ranking = 1keywords = chromosome (Clic here for more details about this article) |
3/50. Supernumerary chromosome inherited from a maternal balanced translocation leading to pure trisomy 9p.We describe a child with a supernumerary chromosome defined as der(9)t(9;22) (q12;p11), resulting in trisomy 9p and trisomy 22p. The mother carried the balanced translocation. In G- and C-banding the derivative chromosome 9 appeared to be dicentric and to contain 22q material. Using in situ hybridization we defined the exact breakpoints of the translocation and ruled out the possibility of a centric fission in the mother's chromosomes.- - - - - - - - - - ranking = 7keywords = chromosome (Clic here for more details about this article) |
4/50. Phenotypic variability of the cat eye syndrome. Case report and review of the literature.We present a male infant with preauricular skin tags and pits, downslanting palpebral fissures, hypertelorism, ectopic anus, hypospadias, and hypoplastic left heart syndrome. The clinical features in our patient show phenotypic overlap with the cat eye syndrome, as illustrated by the review of 105 reported cases. cytogenetic analysis revealed a supernumerary marker chromosome, which was identified by microdissection and fluorescence in situ hybridization as an isodicentric chromosome 22(pter --> q11.2::q11.2 --> pter). It was proved with probes specific for the cat eye syndrome critical region that this region was present in quadruplicate in the propositus. We conclude that CES is characterized by large phenotypic variability, ranging from near normal to severe malformations, as reflected in the neurodevelopmental outcome. Preauricular skin tags and/or pits are the most consistent features, and suggest the presence of a supernumerary bisatellited marker chromosome 22 derived from duplication of the CES critical region.- - - - - - - - - - ranking = 3keywords = chromosome (Clic here for more details about this article) |
5/50. The trisomy 9p syndrome.Since the first description of trisomy 9p in 1970, there has been a rapidly increasing recognition and reporting of new cases. The physical and mental features of retarded growth and development, down-turned corners of the mouth, mildly globular nose, slightly wide-set and deep-set eyes with anti-Mongoloid slant, and unusual dermatoglyphics are distinctive enough to establish trisomy 9p as a clinical chromosomal entity--one which may prove to be the fourth most common autosomal syndrome (after trisomies 21, 13, and 18). This paper includes a review and tabulation of features seen in the 20 reported cases and photographs of the faces of ten of these children. A new case included in this survey demonstrates the practical application of four types of chromosome banding identification (C, G, Q, and R). The confirmation of the chromosomal aberration in this syndrome is dependent on the use of one or more of these special laboratory techniques. Most of the clinical characteristics distinctive of the trisomy 9p syndrome are seen also in other trisomies involving more or less of the number 9 chromosome. From these observations it is determined that the crucial determinants of the classical features of this syndrome lie within the distal half of the number 9 short arm.- - - - - - - - - - ranking = 2keywords = chromosome (Clic here for more details about this article) |
6/50. Roberts syndrome, normal cell division, and normal intelligence.Roberts-SC phocomelia syndrome (RS) is an autosomal recessive disorder of symmetric limb defects, craniofacial abnormalities, pre- and postnatal growth retardation, and mental retardation. patients with RS have been reported to have premature separation of heterochromatin of many chromosomes and abnormalities in the cell-division cycle. No case has been reported who had normal intelligence and normal cell division with typical clinical features of the RS. We report a case of a six-year-old male of clinical and radiologic findings of typical RS with normal cell division and normal intelligence.Although he showed growth retardation, his intelligence was normal. Van Den Berg and Francke later reported that 79 out of 100 cases of Roberts syndrome had premature cell separation (PCS). We think that this case may demonstrate severe expression of the Roberts syndrome even though PCS is not exhibited. The limb involvement of this case was symmetrical, and he showed phocomelia of upper limbs, equinus valgus deformity of ankle, aplasia of fibula, and shortness of fifth toes while his hands and feet were normal with 5 rays each. craniofacial abnormalities of this case were typical; he showed scaphocephaly, mild hypertelorism, mandibular hypoplasia, dysplastic helix of ear, narrowing of external auditory canal, and cleft palate with wide gap.This report supports the theory that normal intelligence can make social-personal adjustment possible even if all of the stigmata of Roberts syndrome is present.- - - - - - - - - - ranking = 1keywords = chromosome (Clic here for more details about this article) |
7/50. Putative monosomy 21 in two patients: clinical findings and investigation using fluorescence in situ hybridization.Complete monosomy 21 is claimed to be a rare chromosomal disorder in which the cytogenetic investigation is bedevilled by technical difficulties. We describe the disparate clinical features in two patients in whom an initial diagnosis of monosomy 21 was made by routine karyotyping. fluorescence in situ hybridisation (FISH) confirmed a translocation of chromosome 21 material to the short arm of chromosome 5 and to the x chromosome, respectively. The usefulness of FISH in the investigation of subtle chromosomal rearrangements is hereby demonstrated. These findings also cast doubt on the existence of "pure" monosomy 21 as an entity, and suggest that partial monosomy 21 is a more likely occurrence.- - - - - - - - - - ranking = 3keywords = chromosome (Clic here for more details about this article) |
8/50. Segregation of a t(1;3) translocation in multiple affected family members with both types of adjacent-1 segregants.A subtle balanced translocation involving the terminal regions of 1q and 3p was identified in a large family by high-resolution karyotype analysis and confirmed by fluorescence in situ hybridization (FISH) analysis. In this family, segregation of a balanced t(1:3)(q42.3;p25) chromosome translocation led to two types of viable unbalanced complements. The proband inherited the derivative chromosome 3, resulting in partial trisomy of 1q and partial monosomy of 3p. A paternal uncle and cousin had the reciprocal rearrangement with a derivative of chromosome 1, resulting in partial monosomy for 1q and partial trisomy for 3p. While profound mental and physical retardation and congenital heart defects were characteristics for both rearrangements, facial dysmorphism was quite distinct for each imbalance. Individuals who had the derivative chromosome 3 had a long face, wide eyebrows, small palpebral fissures, hypertelorism, prominent glabella, a large tip of the nose, long philtrum with thin upper lip, and low set-ears. In contrast, family members with the derivative of chromosome 1 had a tall forehead with bifrontal narrowing, full and large cheeks, and large simple ears. Since the translocated segments are small and approximately equal in size in this family, it is not surprising that viability was seen in individuals with both types of adjacent-1 segregation. In this kindred, the ratio of normal to abnormal individuals born to balanced carriers is believed to be about 1:1.5. This suggests that the recurrence risk for carriers is 50%.- - - - - - - - - - ranking = 5keywords = chromosome (Clic here for more details about this article) |
9/50. Mild developmental delay in terminal chromosome 6p deletion.Deletions involving the short arm of chromosome 6 are relatively rare. Although features of this condition are variable, common findings include developmental delay, ocular abnormalities, hearing loss, and cardiac defects. In an effort to define further the clinical variability of this condition, we report a 6-year-old female with a de novo terminal deletion of chromosome 6 at band 6p24, with mild gross motor delays and normal cognition.- - - - - - - - - - ranking = 6keywords = chromosome (Clic here for more details about this article) |
10/50. A new case of a severe clinical phenotype of the cat-eye syndrome.A new case of severe clinical phenotype of the cat-eye syndrome: We report on a female infant with severe clinical phenotype of Cat-Eye Syndrome (CES). At birth, she had respiratory distress and marked hypotonia. physical examination showed major craniofacial anomalies including microcephaly, bilateral total absence of the external ears, hypertelorism, bilateral ocular coloboma of iris and micrognathia. In addition, she had anal stenosis, a patent ductus arteriosus and intra- and extra- hepatic biliary atresia. She deteriorated with the development of bradycardia. She died at age one month of cardiac failure. cytogenetic analysis of the proband showed an extra de novo small bisatelllited marker chromosome in all cells examined. Molecular cytogenetic analysis with fluorescence in situ hybridization (FISH) identified the marker as a CES chromosome. Thus, the patient's karyotype was: 47, XX, idic(22)(pter-->q11.2 ::q11.2-->pter). The duplication breakpoints giving rise to the CES chromosome were distal to the digeorge syndrome (DGS) locus 22q11.2. The marker could be classed as a type 11 symmetrical (10). According to a recent review of CES literature (1) only 41 % of the CES patients have the combination of iris coloboma, anal anomalies and preauricular anomalies. Almost 60% are hard to recognize by their phenotype alone. Only twelve patients showed a severe clinical phenotype leading to the death of the child. This phenotypic variability increases the difficulties of genetic counseling.- - - - - - - - - - ranking = 3keywords = chromosome (Clic here for more details about this article) |
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