1/89. Delineation of two distinct 6p deletion syndromes.Deletions of the short arm of chromosome 6 are relatively rare, the main features being developmental delay, craniofacial malformations, hypotonia, and defects of the heart and kidney, with hydrocephalus and eye abnormalities occurring in some instances. We present the molecular cytogenetic investigation of six cases with 6p deletions and two cases with unbalanced translocations resulting in monosomy of the distal part of 6p. The breakpoints of the deletions have been determined accurately by using 55 well-mapped probes and fluorescence in situ hybridization (FISH). The cases can be grouped into two distinct categories: interstitial deletions within the 6p22-p24 segment and terminal deletions within the 6p24-pter segment. Characteristics correlating with specific regions are: short neck, clinodactyly or syndactyly, brain, heart and kidney defects with deletions within 6p23-p24; and corneal opacities/iris coloboma/Rieger anomaly, hypertelorism and deafness with deletions of 6p25. The two cases with unbalanced translocations presented with a Larsen-like syndrome including some characteristics of the 6p deletion syndrome, which can be explained by the deletion of 6p25. Such investigation of cytogenetic abnormalities of 6p using FISH techniques and a defined set of probes will allow a direct comparison of reported cases and enable more accurate diagnosis as well as prognosis in patients with 6p deletions.- - - - - - - - - - ranking = 1keywords = hypertelorism (Clic here for more details about this article) |
2/89. Wolf's syndrome in twins -- translocation in the mother.A case of MZ twins, both affected by Wolf's syndrome, is described. Their mother, of subnormal look and low intellectual level is translocated. The children, born with a weight and size much below the average, show a very special morphotype; a hook-nose, an an abnormal conformation of the back edge of the nostrils (a protrusion in the shape of a horn overhanging the filtrum), hypertelorism, microcephaly. Great asynchronism in the maturation of the bones and a somatoschisis of the body of the cervical vertebrae are noted. Deletion of the short arm chromosome 4 is juxtacentromeric. The study of blood and tissue groups corroborates monozygosity. Dermatoglyphs are little abnormal and identical in the two children. The mother's family is phenotypically normal. At 19 months of age, measuring is still below 4, psychomotor progress is extremely weak, and convulsions are frequent.- - - - - - - - - - ranking = 1keywords = hypertelorism (Clic here for more details about this article) |
3/89. 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 = hypertelorism (Clic here for more details about this article) |
4/89. Ophthalmic features of chromosome deletion 4p- (wolf-hirschhorn syndrome).By using the Giemsa banding technique we identified three patients with chromosome deletion 4p-. All had anterior segment anomalies, exotropia, blepharoptosis, antimongoloid palpebral fissures, hypertelorism, and disk abnormalities. One patient (Case 1) had Rieger's anomaly. Some clinical features in patients with 4p- are similar to those in patients with chromosome deletion 5p-, cri-du-chat syndrome, although 4p- individuals do not have the distinctive cry. The ocular features which distinguish 4p- from other deletions include normal tearing, some degree of blepharoptosis, and the preponderance of anterior segment signs.- - - - - - - - - - ranking = 1keywords = hypertelorism (Clic here for more details about this article) |
5/89. Interstitial deletion of bands 11q21-->22.3 in a three-year-old girl defined using fluorescence in situ hybridization on metaphase chromosomes.A 3-year-old girl has a de novo deletion of 11q21-22.3. The patient was studied because of minor anomalies, disproportionate short stature, and developmental delay. The deletion was first detected by conventional cytogenetic analysis and defined further by using chromosome 11-specific YAC clones by fluorescent in situ hybridization (FISH) on metaphase chromosomes. Three YAC clones, 11H7, 4A5, and IH4, were lacking from one of the patient's chromosome 11. Trigonocepahly, hypertelorism, apparently low-set ears, mild renal abnormality, and delay in speech development found in our patient are similar findings in other published interstitial deletion cases. Our study shows that a molecular cytogenetic approach is useful in defining the specific location and the extent of an interstitial deletion in cytogenetically difficult areas such as 11q.- - - - - - - - - - ranking = 1keywords = hypertelorism (Clic here for more details about this article) |
6/89. 11q- syndrome: three cases and a review of the literature.We report on three children with de novo terminal deletions of the long arm of chromosome 11 (11q-) and breakpoints in 11q23-q24. Eighty-nine other patients with partial monosomy 11q have been reported and were reviewed by us. Salient features of 11q- syndrome are psychomotor retardation, trigonocephaly, telecanthus/hypertelorism, broad depressed nasal bridge, micrognathia, low set abnormal ears, cardiac anomalies and hand/foot anomalies. Renal agenesis and anal atresia are reported first here. Supratentorial white matter abnormality on CT and MRI present in our second patient was reported in three patients. Increased mortality is caused by cardiac anomalies. A third of all patients with partial monosomy 11q had thrombocytopenia or pancytopenia and this seems to be related to the absence of band 11q23-q24. Seventy-six percent of patients have de novo deletions with breakpoints in 11q21-q25. There is no obvious correlation between the length of the deleted segment and the severity of the symptoms. In unbalanced chromosomal patterns with deletions of 11q involving bands 11q23-q24 the typical phenotype of 11q- syndrome remains recognizable. Deletions distal to 11q24.1 do not produce the typical 11q- syndrome.- - - - - - - - - - ranking = 1keywords = hypertelorism (Clic here for more details about this article) |
7/89. Familial Del(18p) syndrome.We report on sibs and their mother, all with del(18p). The propositus, an 11-month-old, had developmental delay, round face, hypertelorism, large ears, broad nasal bridge, upturned nostrils, micrognathia, a high palate, redundant skin around the neck, micropenis, and cryptorchidism. The elder sister, a two and 7/12-year-old, had round face, hypertelorism, broad nasal bridge, narrow and high palate, redundant skin around the neck, short fingers, and hypoplastic genitalia. Their mother had microcephaly, hypertelorism, prominent columella, broad nasal bridge, wide mouth, high palate, malaligned teeth, and clinodactyly of the fifth fingers. Serial photographs of the mother showed that the characteristic round face in infancy changed to long face with age. The present report suggests that the mother with del(18p) may be fertile, and proper genetic counseling and long follow-up is necessary for the patient with del(18p) syndrome. copyright Wiley-Liss. Inc.- - - - - - - - - - ranking = 3keywords = hypertelorism (Clic here for more details about this article) |
8/89. A distinctive phenotype associated with an interstitial deletion 6q14 contained within a de novo pericentric inversion 6 (p11.2q15).This report describes a nearly 25-year-old female with an interstitial deletion of band 14 in the long arm of one chromosome 6 (6q14). The deletion is contained within a de novo pericentric inversion with breakpoints in 6p11.2 and 6q15 (karyotype 46,XX, del(6)(q13q15),inv(6)(p11.2q15). The distal breakpoint of the deletion and the pericentric inversion at 6q15 are the same, but the proximal breakpoints differ. Since cells with other chromosomal findings were not detected in cultured lymphocytes and fibroblasts, chromosome mosaicism seems unlikely. Thus, it is assumed that the inversion and the deletion originated from the same event. The development of a distinctive phenotype in the patient was observed over a period of 22 years. It includes characteristic dysmorphic facial features such as ocular hypertelorism, flat nasal bridge, prominent zygomatic bones, and a depressed glabella. A striking, non-progressive deficit of motor control is manifest in an inability to use her hands properly and a broad-based slow-motion-like gait. Although severely deficient in abstract mental abilities and speech development, she is well adapted to family life and to a school for retarded individuals. Normal height and head circumference, and reduced sensitivity to pain are noteworthy. Presumably the deletion caused the phenotype and the distinct behavioral pattern. This patient probably represents a novel chromosomal phenotype that results from aggregate haploinsufficiency of gene loci in the deleted region.- - - - - - - - - - ranking = 1keywords = hypertelorism (Clic here for more details about this article) |
9/89. Axenfeld-Rieger anomaly, hypertelorism, clinodactyly, and cardiac anomalies in sibs with an unbalanced translocation der(6)t(6;8).We describe two sibs with the unbalanced translocation der(6)t(6;8)(p25.1;q24.23), making them monosomic for 6p25.1-->6pter and trisomic for 8q24.23-->8qter. The siblings both possess Axenfeld-Rieger Anomaly (ARA), hypertelorism, clinodactyly, and cardiac anomalies, but otherwise vary in the phenotypic manifestations of this unbalanced translocation. We compare them to previously described cases and a recently proposed syndrome of ARA, atrial septal defect, and sensorineural deafness.- - - - - - - - - - ranking = 5keywords = hypertelorism (Clic here for more details about this article) |
10/89. Terminal 6q25.3 deletion and abnormal behaviour.A 10-year-old mentally retarded boy with terminal 6q25 deletion, dysmorphism and striking abnormal behaviour is reported. The main abnormal physical features recorded at different ages consisted of hydrocephalus, axial hypotonia, absence of spontaneous prehension, long face, synophris, hypertelorism with epicanthic folds, internal alternating strabismus, retinal abnormalities with macular degeneration, beaked nose, long philtrum, high-arched palate, lumbar spina bifida, right paravertebral dimple at the upper sacral region, prominent coccyx, broad thumbs and great toes, fetal pads and cryptorchidism. The special behavioural difficulties were made of restlessness, hyperactivity, obsessive compulsive reactions with a self-injurious tendency and episodes of apparently voluntary vomiting crisis concomitant with stress periods. A review of the available literature strongly suggests that individuals with small chromosomal deletions are at high risk of developing behavioural problems.- - - - - - - - - - ranking = 1keywords = hypertelorism (Clic here for more details about this article) |
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