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F Encha-Razavi

Publications and source records attributed to F Encha-Razavi.

14 recordsLinked to original sources
PubMed2001

Lissencephaly type III, stippled epiphyses and loose, thick skin: a new recessively inherited syndrome.

We report on two new cases of syndromic lissencephaly in two consanguineous sibs, with skeletal abnormality, born to young, healthy, second cousin parents with healthy children. In Case 1, fetal ultrasound screening at 32 weeks of gestation showed microcephaly, skin infiltration and equinovarus feet. MRI disclosed cerebral agyria, hypoplastic cerebral mantle and posterior agenesis of the corpus callosum. The propositus, a boy, died soon after birth at term. In Case 2, fetal ultrasound study performed at 16 weeks of gestation disclosed skin infiltration. MRI at 22 weeks of gestation showed microcephaly with agenesis of corpus callosum and cerebellar hypoplasia. Pregnancy was terminated at 22 weeks of gestation. The fetus had normal 46, XY karyotype and similar anomalies found in the index case, with cranio-facial edema and arthrogryposis. X-ray films showed epiphyseal stippling of cervical vertebrae, feet and sacrum. Metacarpal bones were shortened with hypoplastic distal phalanges. Neuropathological findings were concordant with the pattern described in type III lissencephaly: an agyric brain with hypoplastic brain stem and cerebellum, severe neuronal loss of the cortical plate, matrix zone, basal ganglia, brainstem nuclei and spinal cord with axonal swelling and microcalcification. This entity seems to be a new syndromic lissencephaly type III, because of epiphyseal calcifications and metacarpophalangeal bone dysplasia.

Abnormalities, Multiple↗
PubMed2000

Expression of the PAX2 gene in human embryos and exclusion in the CHARGE syndrome.

The CHARGE syndrome comprises ocular coloboma, heart malformation, choanal atresia, retarded growth and development, central nervous system malformations, genital hypoplasia, ear abnormalities, or deafness. The cause of the CHARGE syndrome remains unknown. In the present study, we analyzed the distribution pattern of the PAX2 gene in human embryos and found that PAX2 gene expression occurs in the primordia affected in the CHARGE syndrome. These data prompted us to consider the PAX2 gene a candidate gene in the CHARGE "association." We analyzed the PAX2 gene in 34 patients fulfilling the diagnostic criteria of the CHARGE syndrome for deletion and nucleotidic variations of the coding sequence and identified only polymorphisms. Our data suggest that mutation of the PAX2 gene is not a cause of the CHARGE association. However, the pattern of expression of PAX2 suggests that genes encoding downstream targets effectors could be candidate genes for the CHARGE syndrome.

Abnormalities, Multiple↗
PubMed2000

Neurological phenotype in Waardenburg syndrome type 4 correlates with novel SOX10 truncating mutations and expression in developing brain.

Waardenburg syndrome type 4 (WS4), also called Shah-Waardenburg syndrome, is a rare neurocristopathy that results from the absence of melanocytes and intrinsic ganglion cells of the terminal hindgut. WS4 is inherited as an autosomal recessive trait attributable to EDN3 or EDNRB mutations. It is inherited as an autosomal dominant condition when SOX10 mutations are involved. We report on three unrelated WS4 patients with growth retardation and an as-yet-unreported neurological phenotype with impairment of both the central and autonomous nervous systems and occasionally neonatal hypotonia and arthrogryposis. Each of the three patients was heterozygous for a SOX10 truncating mutation (Y313X in two patients and S251X [corrected] in one patient). The extended spectrum of the WS4 phenotype is relevant to the brain expression of SOX10 during human embryonic and fetal development. Indeed, the expression of SOX10 in human embryo was not restricted to neural-crest-derived cells but also involved fetal brain cells, most likely of glial origin. These data emphasize the important role of SOX10 in early development of both neural-crest-derived tissues, namely melanocytes, autonomic and enteric nervous systems, and glial cells of the central nervous system.

Autonomic Nervous System↗
PubMed2000

Expression of the sonic hedgehog gene in human embryos with neural tube defects.

BACKGROUND: To estimate the rate of malformations observed during early human development, a series of 38,913 first-trimester abortions were studied. Neural tube defects (NTD) were found in 57 cases. METHODS: A histological study of serial sections performed in 25 embryos revealed a spectrum of axial structure abnormalities. Expression of the SHH gene was studied by in situ hybridization in one case of CRS and in two cases of SB. RESULTS: A cervical notochord duplication was always found in craniorachischisis (CRS, n = 8), but not in spina bifida (SB, n = 10) or diplomyelia (split cord malformation, n = 3). In the embryo with CRS, expression of SHH was found in both domains, corresponding to the duplicated part of the notochord, whereas a single signal was observed in the nonduplicated part. This expression was associated at the cervical level of the open neural tube with a broad SHH expression domain and with two or even three domains in its lumbar region, suggesting multiple functional floor plates. Similarly, in two embryos with SB, two domains of SHH expression were found in the ventral neural tube. CONCLUSIONS: Our findings suggest that notochord splitting in the cervical region might be involved in the pathogenesis of CRS. Interestingly, similar notochord abnormality and altered expression of the shh gene are observed in Lp mice with NTD. This suggests that the Lp gene could be a candidate gene for human CRS. Further studies are needed to establish the primary event responsible for the notochord splitting and for the abnormal expression of the SHH gene in the floor plate in embryos with CRS and SB.

Abortion, Induced↗
PubMed2000

JAGGED1 gene expression during human embryogenesis elucidates the wide phenotypic spectrum of Alagille syndrome.

Mutations of the JAGGED1 gene, encoding a NOTCH receptor ligand, cause Alagille syndrome (AGS), a complex malformative disorder affecting mainly the liver, heart, vertebrae, eye, and face. Minor and occasional features involving kidney, pharynx, systemic arteries, skeleton, and ear are in some cases associated with the syndrome. To describe the expression of JAGGED1 during human embryogenesis and to study its relationship with all the features of AGS, we performed in situ hybridization studies on human embryos and fetal tissue sections. JAGGED1 was mainly expressed in the cardiovascular system. In the liver, JAGGED1 transcripts were only detected in blood vessels. JAGGED1 was also expressed in other structures of mesenchymal origin (distal mesenchyme of limb buds; mesonephric and metanephric tubules of the kidney) and in epithelial structures including the ciliary margin of the retina and the posterior part of the lens, the ventral epithelium of the otic vesicle, the neurosensory epithelium of the ear vestibule, the epithelium of pharyngeal arches, and the developing central nervous system. The strong JAGGED1 expression during human embryo- and feto-genesis both in the vascular system and in other mesenchymal and epithelial tissues implicates abnormal angiogenesis in the pathogenesis of Alagille syndrome and particularly the paucity of interlobular bile ducts. However, it is probably not the only mechanism of the disease. Except for the central nervous system, there is a strong correlation between JAGGED1 expression and all the features of AGS. This implies that the features occasionally associated with the syndrome are not coincidental.

Alagille Syndrome↗
PubMed1998

Expression of the SOX10 gene during human development.

SOX10, a new member of the SOX gene family, is a transcription factor defective in the Dom (Dominant megacolon) mouse and in the human Shah-Waardenburg syndrome. To help unravel its physiological role during human development, we studied SOX10 gene expression in embryonic, fetal, and adult human tissues by Northern blot and in situ hybridization. As in mice, the human SOX10 gene was essentially expressed in the neural crest derivatives that contribute to the formation of the peripheral nervous system, and in the adult central nervous system. Nevertheless, it was more widely expressed in humans than in rodents. The spatial and temporal pattern of SOX10 expression supports an important function in neural crest development.

Blotting, Northern↗
PubMed1997

Different proximal and distal rearrangements of chromosome 7q associated with holoprosencephaly.

Four new cases of holoprosencephaly are described in fetuses exhibiting abnormal karyotypes with different distal and proximal rearrangements of the long arm of chromosome 7. Three of them showed terminal deletions of chromosome 7q, confirming the importance of the 7q36 region in holoprosencephaly. The karyotype of the fourth fetus showed an apparently balanced de novo translocation, t(7;13) (q21.2;q33), without any visible loss of the distal part of chromosome 7q. The involvement of new genes, different from the human Sonic Hedgehog gene (hShh) responsible for holoprosencephaly, or a positional effect are discussed.

Amniocentesis↗
PubMed1997

[Neuropathological study of 134 fetuses in HIV infected mother].

A neuropathological study performed in 134 foetuses from HIV infected mothers, between 16 and 35 weeks of gestation, revealed two cases of hypoxic-ischemic brain damage, related to long labor and drug abuse. Immunostains against HIV proteins were negative in all cases. Nests of migrating cells in the cerebrum and cerebellar heterotopias were found in most cases and were considered to be common findings in fetal brain. Our study clearly showed the absence of cerebral HIV infection during early pregnancy and raises the question of the frequency of vertical transmission during HIV infection. However, the evaluation of cerebral changes in infants with HIV infection should take into consideration the features of the developing brain and the existence of other adverse factors that may interfere with its development during pregnancy.

Brain↗
PubMed1997

[Fetal neuropathology: a new approach].

Recognition of central nervous system (CNS) abnormalities by prenatal imaging has awakened interest in fetal neuropathology, considered as a terra incognita by most pathologists. The evaluation of fetal brains implies a perfect knowledge of the timing and characteristics of the developing and changing nervous system during gestation. Disorders of the brain are now studied with special regard toward their cause analysis considering fetal, maternal, and placental pathology. Thus, with this new approach and the distinction between primary and secondary CNS lesions, an effective genetic counselling has become a realistic goal. Examining fetal brains has led on the other land, to the recognition of distinct entities and the identification of specific chromosomal and/or gene(s) abnormalities.

Brain↗
PubMed1992

Congenital hypothalamic hamartoma syndrome: nosological discussion and minimum diagnostic criteria of a possibly familial form.

We report on congenital hypothalamic hamartomas, discovered at autopsy in 3 unrelated fetuses. In the first 2 patients, the tumor was associated with skeletal dysplasia only. In the third patient, it was part of a non-random congenital malformation association, suggestive of Meckel syndrome. In one family, a previous boy died soon after birth with similar craniofacial and skeletal abnormalities. As far as we know, the association between isolated skeletal dysplasia and congenital hypothalamic hamartomas has not yet been documented in the literature. Nevertheless, a spectrum of skeletal abnormalities has been described in association with congenital hypothalamic "hamartoblastoma" and a constellation of variable visceral malformations under the eponym of "Pallister-Hall syndrome" (PHS). A detailed analysis of the PHS reported cases shows that only skeletal dysplasia and oro-facial abnormalities are present constantly. They show similarities with those found in our first 2 cases. These findings prompt us to consider skeletal dysplasia and oro-facial abnormalities as common denominator and minimum criteria required to define a nosologically distinct, possibly familial entity, which we suggest calling "congenital hypothalamic hamartoma syndrome" (CHHS).

Bone Diseases, Developmental↗
PubMedDate not supplied

Arthrogryposis multiplex congenita and cerebellopontine ischemic lesions in sibs: recurrence of prenatal disruptive brain lesions with different patterns of expression?

Arthrogryposis multiplex congenita (AMC) is a heterogeneous group of disorders in which prolonged decrease or absence of fetal movements results in a series of deformational anomalies. The rate of recurrence ranges from 25% in some recessive forms of myogenic arthrogryposis or of primary anterior horn cell loss, to less than 1% in anoxic-ischaemic damage. Cerebral clastic processes are considered as sporadic. We report on a non-consanguineous family in which the first child was affected by AMC and the following pregnancy was terminated because cerebellum hypoplasia was suspected at ultrasound and confirmed by fetal magnetic resonance imaging. Post-mortem findings demonstrated pontocerebellar ischaemic-haemorrhagic injuries. The occurrence of these neurologic abnormalities in the same family suggests a common mechanism, which might correspond to a same genetic defect with different patterns of expression. This is the first prenatal report suggesting that an 'ischaemic' process, usually recognised as sporadic could in fact be due to an inherited abnormality. Careful prenatal follow-up of third-trimester fetal brain development may be required in pregnant women with a family history of AMC.

Adult↗