1/7. 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 = hypertelorism (Clic here for more details about this article) |
2/7. prenatal diagnosis of trisomy 18p and distal 21q22.3 deletion.OBJECTIVES: To present the perinatal findings and molecular cytogenetic analysis of concomitant trisomy 18p (18p11.2-->pter) and distal 21q22.3 deletion. CASE AND methods: A 29-year-old woman, gravida 2 para 1, underwent amniocentesis at 17 weeks' gestation because she was a carrier of a balanced reciprocal translocation, 46,XX,t(18;21)(p11.2;q22.3). cytogenetic analysis of the cultured amniocytes revealed a karyotype of 46,XX,der(21)t(18;21)(p11.2;q22.3). The fetus had a derivative chromosome 21 with an extra short arm of chromosome 18 attached to the terminal region of the long arm of chromosome 21. Level II sonograms did not find prominent structural anomalies. The pregnancy was terminated subsequently. At autopsy, the proband displayed a mild phenotype of hypertelorism, a small mouth, micrognathia, a narrowly arched palate, low-set ears, and clinodactyly. The brain and other organs were unremarkable. Genetic marker analysis showed a distal deletion at 21q22.3 and a breakpoint between D21S53 (present) and D21S212 (absent), centromeric to the known holoprosencephaly (HPE) minimal critical region D21S113-21qter. CONCLUSION: Genetic marker analysis helps in delineating the region of deletion in prenatally detected unbalanced cryptic translocation. Fetuses with concomitant trisomy 18p and distal 21q22.3 deletion may manifest inapparent phenotypic abnormalities in utero. haploinsufficiency of the HPE critical region at 21q22.3 may not cause an HPE phenotype.- - - - - - - - - - ranking = 0.16666666666667keywords = hypertelorism (Clic here for more details about this article) |
3/7. De novo satellited 21q associated with corpus callosum dysgenesis, colpocephaly, a concealed penis, congenital heart defects, and developmental delay.De novo satellited 21q associated with corpus callosum dysgenesis, colpocephaly, a concealed penis, congenital heart defects, and developmental delay: We present clinical and cytogenetic data on an infant with de novo satellited 21 q. A 3-month-old boy was found to have microcephaly, developmental delay, hypertelorism, down-slanting palpebral fissures, large low-set ears, a prominent nose, a broad philtrum, a concealed penis, interventricular septal defects, corpus callosum dysgenesis, colpocephaly, ventriculomegaly, and a de novo karyotype of 46,XY,21qs. Standard Ag-NOR staining and FISH studies confirmed a satellite and a deletion on the long arm of a chromosome 21. Quantitative-fluorescent polymerase chain reaction using the polymorphic small tandem repeat markers specific for chromosome 21 determined a maternal origin of the deletion and the breakpoint between D21S156 (21q22.1) (present) and D21S53 (21q22.3) (absent), centromeric to the known minimal holoprosencephaly critical region, D21S13-21qter. The present case provides evidence of the correlation of a distal region of chromosome 21 to the phenotypic effects of monosomy 21.- - - - - - - - - - ranking = 0.16666666666667keywords = hypertelorism (Clic here for more details about this article) |
4/7. Lambotte syndrome: microcephaly, holoprosencephaly, intrauterine growth retardation, facial anomalies, and early lethality--a new sublethal multiple congenital anomaly/mental retardation syndrome in four sibs.We report on an Arabic sibship originating from morocco in which four children manifest an undiagnosed sublethal multiple congenital anomaly/mental retardation (MCA/MR) syndrome of intrauterine growth retardation (IUGR), microcephaly, large soft pinnae, telecanthus or true hypertelorism with squint, flat face, unusual hooked nose, very narrow mouth, retrognathia, and extremely severe neurologic impairment. One child was stillborn. Three others died in a cachectic state during their second year. One child had a severe cerebral malformation compatible with semilobar holoprosencephaly. Other inconstant manifestations are anterior chamber cleavage defect, preaxial polydactyly of feet, interventricular septal defect, and atresia of the external auditory meatus. Autosomal recessive inheritance is likely.- - - - - - - - - - ranking = 0.16666666666667keywords = hypertelorism (Clic here for more details about this article) |
5/7. Trilobar holoprosencephaly ("triprosencephaly"): a unique type of cerebral malformation.Little is known about the neuropathology of the median facial cleft syndrome, which presents as a combination of a wide range of teratological manifestations. We report a unique type of cerebral malformation combined with the median facial cleft syndrome in a 7-day-old female infant with malformations of toes and fingers, hypertelorism and a median cleft nose, as well as a frontally protruding, dorsomedian hornlike cele. At autopsy, the cranium presented facial clefts and bony defects, resulting in partitioning of the anterior cranial fossa into three compartments. The brain had malformative features of lobar holoprosencephaly combined with tripartition of frontal lobes, including an encephalomeningocystocele originating from a right accessory frontal lobe.- - - - - - - - - - ranking = 0.16666666666667keywords = hypertelorism (Clic here for more details about this article) |
6/7. Identification of Sonic hedgehog as a candidate gene responsible for holoprosencephaly.holoprosencephaly (HPE) is a genetically and phenotypically heterogenous disorder involving the development of forebrain and midface, with an incidence of 1:16,000 live born and 1:250 induced abortions. This disorder is associated with several distinct facies and phenotypic variability: in the most extreme cases, anophthalmia or cyclopia is evident along with a congenital absence of the mature nose. The less severe form features facial dysmorphia characterized by ocular hypertelorism, defects of the upper lip and/or nose, and absence of the olfactory nerves or corpus callosum. Several intermediate phenotypes involving both the brain and face have been described. One of the gene loci, HPE3, maps to the terminal band of chromosome 7. We have performed extensive physical mapping studies and established a critical interval for HPE3, and subsequently identified the sonic hedgehog (SHH) gene as the prime candidate for the disorder. SHH lies within 15-250 kilobases (kb) of chromosomal rearrangements associated with HPE, suggesting that a 'position effect' has an important role in the aetiology of HPE. As detailed in the accompanying report, this role for SHH is confirmed by the detection of point mutations in hereditary HPE patients.- - - - - - - - - - ranking = 0.16666666666667keywords = hypertelorism (Clic here for more details about this article) |
7/7. association of holoprosencephaly, ectrodactyly, cleft lip/cleft palate and hypertelorism: a possible third case.We describe a male patient with holoprosencephaly, ectrodactyly, cleft lip/cleft palate and hypertelorism. This rare association has previously been reported in two patients. We present a third case and propose a new association representing a distinguishable entity.- - - - - - - - - - ranking = 0.83333333333333keywords = hypertelorism (Clic here for more details about this article) |