Search

We investigated three families whose offspring had extreme microcephaly at birth and profound mental retardation. Brain scans and postmortem data showed that affected individuals had brains less than 10% of expected size (≤10 standard deviation) and that in addition to a massive reduction in neuron production they displayed partially deficient cortical lamination (microlissencephaly). Other body systems were apparently unaffected and overall growth was normal. We found two distinct homozygous mutations of NDE1, c.83+1G>T (p.Ala29GlnfsX114) in a Turkish family and c.684_685del (p.Pro229TrpfsX85) in two families of Pakistani origin. Using patient cells, we found that c.83+1G>T led to the use of a novel splice site and to a frameshift after NDE1 exon 2. Transfection of tagged NDE1 constructs showed that the c.684_685del mutation resulted in a NDE1 that was unable to localize to the centrosome. By staining a patient-derived cell line that carried the c.83+1G>T mutation, we found that this endogeneously expressed mutated protein equally failed to localize to the centrosome. By examining human and mouse embryonic brains, we determined that NDE1 is highly expressed in neuroepithelial cells of the developing cerebral cortex, particularly at the centrosome. We show that NDE1 accumulates on the mitotic spindle of apical neural precursors in early neurogenesis. Thus, NDE1 deficiency causes both a severe failure of neurogenesis and a deficiency in cortical lamination. Our data further highlight the importance of the centrosome in multiple aspects of neurodevelopment., (Copyright © 2011 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

GPR56 mutations cause an autosomal recessive polymicrogyria syndrome that has distinctive radiological features combining bilateral frontoparietal polymicrogyria, white matter abnormalities and cerebellar hypoplasia. Recent investigations of a GPR56 knockout mouse model suggest that bilateral bifrontoparietal polymicrogyria shares some features of the cobblestone brain malformation and demonstrate that loss of GPR56 leads to a dysregulation of the maintenance of the pial basement membrane integrity in the forebrain and the rostral cerebellum. In light of these findings and other data in the literature, this study aimed to refine the clinical features with the first description of a foetopathological case and to define the range of cobblestone-like features in GPR56 bilateral bifrontoparietal polymicrogyria in a sample of 14 patients. We identified homozygous GPR56 mutations in 14 patients from eight consanguineous families with typical bilateral bifrontoparietal polymicrogyria and in one foetal case, out of 30 patients with bifrontoparietal polymicrogyria referred for molecular screening. The foetal case, which was terminated at 35 weeks of gestation in view of suspicion of Walker Warburg syndrome, showed a cobblestone-like lissencephaly with a succession of normal, polymicrogyric and 'cobblestone-like' cortex with ectopic neuronal overmigration, agenesis of the cerebellar vermis and hypoplastic cerebellar hemispheres with additional neuronal overmigration in the pons and the cerebellar cortex. The 14 patients with GPR56 mutations (median 8.25 years, range 1.5-33 years) were phenotypically homogeneous with a distinctive clinical course characterized by pseudomyopathic behaviour at onset that subsequently evolved into severe mental and motor retardation. Generalized seizures (12/14) occurred later with onset ranging from 2.5 to 10 years with consistent electroencephalogram findings of predominantly anterior bursts of low amplitude α-like activity. Neuroimaging demonstrated a common phenotype with bilateral frontoparietally predominant polymicrogyria (13/13), cerebellar dysplasia with cysts mainly affecting the superior vermis (11/13) and patchy to diffuse myelination abnormalities (13/13). Additionally, the white matter abnormalities showed a peculiar evolution from severe hypomyelination at 4 months to patchy lesions later in childhood. Taken as a whole, these observations collectively demonstrate that GPR56 bilateral bifrontoparietal polymicrogyria combines all the features of a cobblestone-like lissencephaly and also suggest that GRP56-related defects produce a phenotypic continuum ranging from bilateral bifrontoparietal polymicrogyria to cobblestone-like lissencephaly.

Aortic dissection (AD) is a disease characterized by tear of the aortic intimal layer and separation of the arterial wall. Some risk factor such as hypertension and Marfan syndrome is well known in AD. However, the role of genetic factors in AD is largely unknown. Insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene is associated with cardiovascular diseases; patients with D allele have higher serum and tissue ACE levels. We investigated the relationship between the I/D polymorphism of the ACE gene and non-syndromic acute AD. Sixteen patients diagnosed with AD were included in the study (mean age: 60.1 +/- 6.2 years). The diagnosis was established by clinical evaluation and imaging techniques. The control group consisted of 22 age-matched patients without AD (60.9 +/- 7.3 years), who suffered from chest pain. Incidence of hypertension was similar in dissection and control groups (62% vs. 59%). The I/D polymorphism was investigated in both groups by PCR analysis. Dissection types according to the DeBakey classification were identified as type 1 (proximal + distal) in 7 patients (43%), type 2 (proximal) in 5 patients (31%), and type 3 (distal) in 4 patients (25%). The D/D and D/I polymorphisms are present in 13 and 3 AD patients, respectively. None of patients with AD have the II polymorphism. The frequencies of the D allele (DD + ID) are significantly higher in dissection group than control (100% vs. 68%, P < 0001). These results indicate that the D allele of ACE gene is a risk factor for AD.

Objective: Clinical features of the distal 10q trisomy syndrome consist of mental retardation, facial dysmorphism and renal and cardiac anomalies. The presence of a sacrococcygeal teratoma (SCT) in a fetus with distal 10q trisomy has not been reported yet., Methods: A 33-year-old, G5, P2 woman with a singleton pregnancy was referred to our clinic at 24 weeks of gestation for further evaluation of a fetal sacral exophytic mass. Detailed fetal sonographic examination together with chromosomal analysis by amniocentesis was performed., Results: The scan revealed a large SCT together with a persistent right umbilical vein, cardiomegaly, bilateral mild hydronephrosis and intrauterine growth retardation. The fetal karyotype showed distal 10q trisomy (10q24.3-->qter) distal monosomy 17 (p13-->pter). The fetus died after a preterm delivery at 28 weeks of gestation. Postnatal examination confirmed the prenatal findings and added the typical facial features of this syndrome, which consisted of prominent forehead, small nose with depressed nasal bridge, micrognathia and bow-shaped mouth., Conclusion: This case provides further evidence of a possible association between chromosomal aberrations in SCTs.

We report a prenatal diagnosis of a fetus with partial trisomy 7p. Ultrasonography at 28 weeks of gestation of a 27-year-old multigravid woman revealed a growth-retarded fetus with agenesis of the corpus callosum, enlarged left kidney, single umbilical artery, hypertelorism, depressed nasal bridge, frontal bossing, irregular maxiller alveolar composition, club feet, flexion deformity of the upper extremities and Epstein anomaly. Fetal karyotype was 46,XX,der(9)add(9p24),16qh+. Our results indicated that the fetus had an unbalanced translocation, which resulted in duplication of the proximal segment of 7p. Maternal karyotype was (46,XX,t(7,9)(p15.3,p24),16qh+). Because fetal death occurred at 31 weeks of gestation, induction of labor was performed. An enlarged anterior fontanel and micrognathia were seen during fetal autopsy. Trisomy 7p is related to a well-known clinical picture with a dismal prognosis. Our report showed that the outcome of the affected pregnancy may also be poor. Detection of fetal chromosomal abnormality and parental translocations are essential for counseling of the parents., ((c) 2007 S. Karger AG, Basel.)