Significant Phenotypic Variability of Muenke Syndrome in Identical Twins
Medical Genetics and Neurodevelopmental Center, St. Vincent Children's Hospital, Indianapolis, Indiana, USA.American Journal of Medical Genetics Part A (Impact Factor: 2.16). 06/2009; 149A(6):1273-6. DOI: 10.1002/ajmg.a.32841
Muenke syndrome (MS), also known as Muenke nonsyndromic coronal craniosynostosis, is an autosomal dominant condition which can be distinguished from the more common forms of acrocephalosyndactyly but presents a significant variable phenotype. We report on a set of identical twins with a de novo C749G mutation in the FGFR3 gene codon 250 after a pregnancy complicated by prenatal exposure to Nortriptyline. These patients illustrate the variable expressivity of MS in association with an identical gene mutation.
Conference Paper: CMOS ASK system modulation dedicated to cochlear prosthesis[Show abstract] [Hide abstract]
ABSTRACT: In this paper, we propose a modulator and a demodulator which are suitable for a digital data transmission chain for cochlear prostheses. This 'ASK' (amplitude shift keying) type of modulation system would be integrated later with CMOS technology. Such integration involves the external part (modulator) as well as in the internal circuit of the cochlear implant (demodulator). Transmitted digital data would be modulated by the external part with a carrier frequency of 20 MHz. They would be transmitted then in 'RF' to the internal part of the prosthesis through an inductive link at 1 Kbits/s data rate. The conception has been achieved completely in CMOS in order to minimize the energy consumption as well as the occupation area in the desired integrated circuit. The architecture presented in this article has been validated by simulations on the PSPICE software tool using a 0.35μm CMOS technology.
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ABSTRACT: "Core-rod myopathy" is a rare congenital myopathy characterized by the presence of "cores" and "rods" in distinct locations in the same or different muscle fibres. This association is linked currently to mutations in RYR1, NEB and ACTA1 genes. We report identical twins who presented with polyhydramnios and loss of fetal motility during pregnancy; hypotonia, arthrogryposis and swallowing impairment at birth; need of immediate respiratory support and death at 27 and 50 days of life. Muscle biopsies, performed at 27 days of life in twin 1 and at 49 days in twin 2, showed the presence of separate cores and rods in the muscle fibres, both at light and electron microscopy. The molecular analysis showed a heterozygous de novo mutation (Ile4898Thr) of the RYR1 gene. The molecular study of ACTA1, TMP2 and TMP3 genes did not show abnormalities. This is the first report of a lethal form of congenital "core-rod myopathy". The mutation Ile4898Thr has been previously described in central core disease but not in core-rod myopathy. The report enlarges the phenotypic spectrum of "core-rod myopathy" and highlights the morphological variability associated to special RYR1 mutations.
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ABSTRACT: We describe a 2-year-old boy born to healthy, consanguineous parents. He had craniofacial asymmetry with left frontal bossing, midface hypoplasia, proptosis, and low-set ears. In addition, he had curly, light hair, and oval hypomelanotic patches in the abdomen, lower limbs and back and one hyperpigmented patch in the groin without acanthosis nigricans. Cranial three-dimensional CT scan showed right-coronal, sagittal, and lambdoid suture synostoses. His cranial MRI at 2-months of age showed left hemimegalencephaly, hypoplasia of corpus callosum, and an abnormal configuration of hippocampus. In spite of these cranial findings, he had mild developmental delay and his neurological examination showed symmetric strength, tone and reflexes. Apart from febrile seizures, there was no history of epilepsy. The proband developed asymmetric hydrocephalus at the age of 18 months that required third ventriculostomy. Post-operative cranial MRI showed Chiari I- like malformation and asymmetry of cerebral hemispheres but less dysplastic cerebral cortex. Mutation analysis of FGFR3 showed a c.749C > G, p.Pro250Arg substitution. To the best of our knowledge, these manifestations have not been reported in patients with Muenke syndrome.
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