Functional plasticity of language-related brain areas after cochlear implantation

Using PET, the cerebral network engaged by heard language processing in normal hearing subjects was compared with that in patients who received a cochlear implant after a period of profound deafness. The experimental conditions were words, syllables and environmental sounds, each controlled by a noise baseline. Four categories of effect were observed: (i) regions that were recruited by patients and controls under identical task conditions: the left and right superior temporal cortices and the left insula were activated in both groups in all conditions; (ii) new regions, which were recruited by patients only: the left dorsal occipital cortex showed systematic activation in all conditions versus noise baselines; (iii) regions that were recruited by both groups with a different functional specificity; e.g. Wernicke's area responded specifically to speech sounds in controls but was not specialized in patients; and (iv) regions that were activated in one group more than the other: the precuneus and parahippocampal gyrus (patients more than controls) and the left inferior frontal, left posterior inferior temporal and left and right temporoparietal junction regions (controls more than patients). These data provide evidence for altered functional specificity of the superior temporal cortex, flexible recruitment of brain regions located within and outside the classical language areas and automatic contribution of visual regions to sound recognition in implant patients.

Cross-modal plasticity underpins language recovery after cochlear implantation

Postlingually deaf subjects learn the meaning of sounds after cochlear implantation by forming new associations between sounds and their sources. Implants generate coarse frequency responses, preventing place-coding fine enough to discriminate sounds with similar temporal characteristics, e.g., buck/duck. This limitation imposes a dependency on visual cues, e.g., lipreading. We hypothesized that cross-modal facilitation results from engagement of the visual cortex by purely auditory tasks. In four functional neuroimaging experiments, we show recruitment of early visual cortex (V1/V2) when cochlear implant users listen to sounds with eyes closed. Activity in visual cortex evolved in a stimulus-specific manner as a function of time from implantation reflecting experience-dependent adaptations in the postimplant phase.

Isolation of Golgi membranes from tissues and cells by differential and density gradient centrifugation

This unit describes the isolation of Golgi membranes on a preparative basis. Methods are provided for rapid isolation of dextran-treated Golgi stacks from rat liver using a sucrose density barrier, and Golgi isolation by floatation from a light mitochondrial fraction, along with an alternate procedure using a self-generated iodixinol gradient. If the Golgi tends to vesiculate during homogenization (commonly the case with cultured cells), a primary requirement is to separate these vesicles from other microsomal compartments, so a procedure is described for a discontinuous gradient of sucrose for cultured cells, and an alternate protocol describes a continuous iodixinol gradient that may provide greater resolution. A self-generated iodixinol gradient is described to prepare Golgi membranes from a microsomal fraction of rat hepatocytes, and a standard Golgi enzyme marker assay is given in a support protocol.

Is there a functioning vestibulocochlear nerve? Cochlear implantation in a child with symmetrical auditory findings but asymmetric imaging

The finding of an abnormally narrow internal auditory meatus during the assessment of a child for cochlear implantation raises the possibility that the meatus may not contain the normal number of nerves. Even with currently available MRI techniques it may be extremely difficult to decide whether or not to offer cochlear implant in such cases. We present a child of 4 1/2 years, assessed for cochlear implantation. MRI and CT imaging suggested aplasia of one vestibulocochlear nerve and hypoplasia of the other. However, audiological tests showed clear responses to sound in both ears and functional use of sound in her daily life. This child was eventually implanted with encouraging postoperative results.

Subtle radiographic findings of achondroplasia in patients with Crouzon syndrome with acanthosis nigricans due to an Ala391Glu substitution in FGFR3

A unique type of craniofacial dysostosis, Crouzon syndrome with acanthosis nigricans (CAN), has been attributed to a specific substitution (Ala391Glu) in the fibroblast growth factor receptor 3 (FGFR3) gene. At birth, individuals with this disorder have craniosynostosis, ocular proptosis, midface hypoplasia, choanal atresia, hydrocephalus, and they experience the onset of acanthosis nigricans during childhood. We report three cases and compare the clinical characteristics of our cases with the previously reported cases of this disorder. Since the Ala391Glu substitution in FGFR3 is close to the substitutions in the transmembrane domain that result in achondroplasia, we carefully reviewed the skeletal findings in six patients. We identified subtle radiographic findings of achondroplasia in all six cases including narrow sacrosciatic notches, short vertebral bodies, lack of the normal increase in interpediculate distance from the upper lumbar vertebrae caudally, and broad, short metacarpals and phalanges. Even before acanthosis nigricans appears, the presence of choanal atresia and hydrocephalus in an individual with features of Crouzon syndrome should suggest the diagnosis of CAN, and subtle skeletal findings can lend further support to this diagnosis.

Radiographic findings and Gs-alpha bioactivity studies and mutation screening in acrodysostosis indicate a different etiology from pseudohypoparathyroidism

Acrodysostosis is an uncommon skeletal dysplasia associated with nasal hypoplasia, midface deficiency, severe brachydactyly, and varying degrees of hearing loss and mental retardation. Previous publications have suggested that it may be difficult to distinguish acrodystostosis from pseudohypoparathyroidism on clinical grounds, but acrodysostosis does appear to have distinct clinical and radiologic findings. Spinal stenosis is an underappreciated risk in acrodysostosis, despite the reported loss of normal caudal widening of the lumbar interpediculate distance on AP spine radiographs in the original report of this disorder by Robinow et al., with confirmation of these radiographic findings by Butler et al. We report two sporadic cases of acrodysostosis, one of which required decompressive laminectomy for symptomatic spinal stenosis, and review 11 cases of acrodysostosis from 9 families that were submitted to the International Skeletal Dysplasia Registry. The objective of this report is to determine the frequency and severity of spinal stenosis in patients with acrodysostosis and to summarize the clinical and radiographic findings of acrodysostosis in an effort to distinguish acrodysostosis clearly from pseudohypoparathyroidism. The pattern of brachydactyly differs between these two conditions, and varying degrees of spinal stenosis are characteristic of acrodysostosis. Both our index patients with acrodysostosis had normal bioactivity of the alpha subunit of the Gs protein, therefore indicating that acrodysostosis has a different pathogenesis from pseudohypoparathyroidism. Furthermore, single-strand confirmational polymorphism (SSCP) analysis failed to demonstrate any confirmational alterations in the coding exons of the Gs alpha gene. These radiographic and laboratory findings substantiate that acrodysostosis is clinically different from pseudohypoparathyroidism and that it is necessary to follow patients with acrodysostosis for signs of spinal stenosis.

Brain iron deposition in Parkinson's disease imaged using the PRIME magnetic resonance sequence

Iron content of the basal ganglia was investigated in 25 patients with idiopathic Parkinson's disease and 14 matched healthy control subjects using a partially refocused interleaved multiple echo sequence on a 1.5 Tesla MRI system. R(2)* (1/T(2)*) and R(2)' (1/T(2)') relaxation rates were higher in the substantia nigra of patients with Parkinson's disease, which indicates that iron content is elevated in this region. R(2)' was lower in the putamen, indicating reduced iron levels; reduction in this region was positively correlated with disease duration. Iron-related oxidative stress may contribute to the neurodegeneration of Parkinson's disease, which may lead to alterations in the iron levels of the striatum. We describe a simple, non-invasive technique for measuring iron content.

Blaschkolinear skin pigmentary variation due to trisomy 7 mosaicism

Mosaic trisomy 7 is a rare condition that can be seen in individuals with Blaschkolinear skin pigmentary variation, somatic asymmetry, and variable other clinical anomalies. In any patient presenting with Blaschkolinear skin pigmentary variation, varying degrees of asymmetrical growth disturbance, developmental delay, and a normal lymphocytic karyotype, chromosomal mosaicism may be present. To rule out tissue-specific or occult chromosomal mosaicism, it is recommended to culture and karyotype skin fibroblasts, since lymphocyte cell lines may not demonstrate the abnormal cell line. Early diagnosis is of paramount importance, since early physical, occupational, and speech/language therapy can greatly improve the developmental outcome of these patients. We report on a fourth patient with trisomy 7 mosaicism in whom early diagnosis and developmental therapy contributed to an improved developmental outcome when compared with patients in previous reports. Early intervention can greatly benefit patients with this diagnosis, especially in minimizing the aggressive behavior associated with communication difficulties. Our patient has milder manifestations than the previously reported patients with no seizure activity or asymmetry and fewer cells with trisomy 7.

Cole-Hughes macrocephaly syndrome and associated autistic manifestations

Based on cases that had been excluded from a previous clinical study of Sotos syndrome, Cole and Hughes [1991: Am J Med Genet 41:115-124] reported a new syndrome associated with marked obesity, occasional delayed bone age, distinctive facial anomalies, mental retardation, and progressive postnatal macrocephaly in the context of autosomal dominant familial macrocephaly. Subsequently, Stevenson et al. [1997: Lancet 349:1744-1745] emphasized the association of progressive postnatal macrocephaly with autism, and they suggested that this might comprise a recognizable autism syndrome. We report two additional patients with Cole-Hughes syndrome and associated autistic characteristics with attention deficit hyperactivity disorder. These patients seem to manifest a distinctive behavioral phenotype associated with Cole-Hughes syndrome and they manifest a distinct subgroup of persons with autism that may ultimately shed light on the pathogenesis of this disorder.

Congenital malformations of the ear and cochlear implantation in children: review and temporal bone report of common cavity

The objective of this review is to analyze aspects of congenital malformation of the ear in relation to cochlear implantation in children. Having briefly described the in utero development of the ear and the classification of types of external, middle and inner ear malformation, five practical aspects of these malformations are discussed. It seems likely that the combination of bilateral profound sensorineural deafness with bilateral microtia severe enough to make a surgical approach to the cochlea difficult will be extremely uncommon. No such cases have been reported, although Klippel-Feil deformity seems the syndrome most likely to produce this set of circumstances. Abnormalities in the intratympanic course of the facial nerve have been associated with cochlear malformation, emphasizing the benefit of intra-operative facial nerve monitoring, and a technique suggested for safely avoiding an abnormally placed nerve. Fistulae of cerebrospinal fluid (CSF) and perilymph can complicate surgery and are relatively common in common cavity and Mondini malformations. Strategies for facilitating surgery in the presence of 'gushers', for measuring the pressure of a gusher and for placement of the cochlear implant electrode array are reviewed, with reports of fluctuating levels of electric current when implants lie in dysplastic cochleas. The relationship of implant performance to VIIIth nerve tissue in malformed cochleas is discussed, with a description of the histological findings in a common cavity cochlea. Techniques for identifying the absence of the cochlear nerve are reviewed. Stimulation of the facial nerve by cochlear implants has been described in cases of congenital malformation of the labyrinth but is relatively uncommon. Case reports of the benefit received by implanted children with congenital cochlear malformation have appeared since 1988. Most cases reported have not yet been followed for long enough to establish a clear picture of the outcome following cochlear implantation in such children; no centre has yet built up a large series of cases, but there have been two multicentre postal surveys. It seems likely that in cochlear malformation the range of potential outcomes in terms of hearing threshold and the development of speech perception and production will be similar to the range found in implanted children without cochlear dysplasia. However there is, as yet, no clear picture of the mean level of performance within this range.

Association study of dopamine receptor gene polymorphisms with drug-induced hallucinations in patients with idiopathic Parkinson's disease

Some patients with idiopathic Parkinson's disease experience hallucinations as a result of treatment with levodopa and dopamine agonists. There is evidence for some heterogeneity in these hallucinating patients based on duration of Parkinson's disease at onset of hallucinations. We compared the frequency of polymorphisms in the dopamine D2 and D3 receptor genes between patients with drug-induced hallucinations and non-hallucinating patients. Two polymorphisms close to DRD2 and one in DRD3 were studied. No association was found with the whole group of hallucinating patients and their controls. However, an association was found with late-onset hallucinations and the C allele of the TaqIA polymorphism, 10.5 kb 3' to DRD2. This polymorphism may be in linkage disequilibrium with a mutation in DRD2 or a nearby gene that predisposes to drug-induced hallucinations which occur later in the course of idiopathic Parkinson's disease.

Familial lissencephaly with cleft palate and severe cerebellar hypoplasia

Lissencephaly is a brain malformation characterized by absence of gyral formation, resulting in a smooth brain surface. Histologic study shows severe anomalies of cerebral cortical development. Several lissencephaly syndromes have been described. Here we report a familial syndrome of lissencephaly, cleft palate, diffuse agyria, and severe cerebellar hypoplasia. Microscopic examination of the abnormally thick cerebral cortex showed absence of cortical layering, with preservation of the pia-glial barrier. This is the first report of recurrent lissencephaly with cleft palate and severe cerebellar hypoplasia in which these unique neuropathology findings are described. Autosomal recessive inheritance is suggested by recurrence in sibs within the same family, but germ cell mosaicism for a dominant mutation is not excluded.

Separation of the intracellular secretory compartment of rat liver and isolated rat hepatocytes in a single step using self-generating gradients of iodixanol

A novel method is described for the separation on a single gradient of the major intracellular organelles of the secretory pathway, the Golgi, the smooth endoplasmic reticulum, and the rough endoplasmic reticulum. Total microsomes were prepared from rat liver by differential centrifugation and resuspended in 20% iodixanol. The microsomal suspension was then layered between a 30% iodixanol cushion and a layer of 15% iodixanol and centrifuged in a vertical rotor for 2 h. The microsomes distributed in four visible bands. The gradients were collected by upward displacement and were characterized (i) by determination of UDP galactose-galactosyltransferase (Golgi marker) NADPH-cytochrome c reductase (endoplasmic reticulum marker) and RNA (rough endoplasmic reticulum marker); (ii) by immunoblotting for TGN38 (trans-Golgi marker) and GS28 (cis-Golgi marker) and for protein disulfide isomerase (endoplasmic reticulum lumenal marker); (iii) by determination of the lipid composition; and (iv) by electron microscopy. The results suggest that the top band (density 1.045-1. 090 g/ml), which contains 68% of the galactosyltransferase activity, consists of vesicles derived from the Golgi. The second broad band in the middle of the tube (density 1.130-1.160 g/ml), which contains 54% of the NADPH-cytochrome c reductase activity, consists mainly of vesicles derived from the smooth endoplasmic reticulum, overlapped at the top by a small band of Golgi-derived lamellae. The two bands at the bottom of the tube (density 1.130-1.160 and density 1.180-1. 220 g/ml) appear to contain two subfractions of vesicles derived from the rough endoplasmic reticulum.

Clinical and behavioral characteristics in FG syndrome

FG syndrome is a rare X-linked recessive form of mental retardation, first described by Opitz and Kaveggia in 1974. Based on over 50 reported cases, FG syndrome is associated with agenesis of the corpus callosum, minor facial anomalies (high, broad forehead with frontal cowlick, ocular hypertelorism, down-slanted palpebral fissures, and small cupped auricles), relative macrocephaly, broad thumbs and halluces, and prominent fetal fingertip pads. Affected individuals manifest neonatal hypotonia and severe constipation, which usually resolves during mid-childhood. The hypotonia with joint hyperlaxity evolves into spasticity with joint contractures in later life. Affability, hyperactivity, and excessive talkativeness are noted frequently in patients with FG syndrome. Recently, we described three additional families (six additional patients) with FG syndrome who support the localization of a gene for the FG syndrome in chromosome region Xq12-q21 [Graham JM Jr, Tackels D, Dibbern K, Superneau D, Rodgers C, Corning K, Schwartz CE. 1998. Am J Med Genet 80:145-156.]. Using these same families and one additional sporadic case of FG syndrome, we compared behavioral and personality characteristics of 6 FG boys with other boys with syndromic and nonsyndromic mental retardation: eight with Down syndrome, seven with Prader-Willi syndrome, eight with nonspecific mental retardation, and 13 with Williams syndrome. Using the Vineland Adaptive Behavior Scales, the Reiss Personality Profiles, and the Achenbach Child Behavior Checklist, parents were asked to characterize the behavior and personality of their boys from ages 4 to 10 years. When compared with Williams syndrome, the FG boys had fewer internalizing behaviors and were significantly less anxious and withdrawn but had similar socially oriented, attention-seeking behaviors. On the Reiss Profile, FG boys were also quite similar to Williams syndrome boys. On the Vineland Scales, FG boys demonstrated significant relative strengths in their socialization skills, consistent with their personality, tending to confirm previous descriptions of their personalities.

PTEN mutation spectrum and genotype-phenotype correlations in Bannayan-Riley-Ruvalcaba syndrome suggest a single entity with Cowden syndrome

Germline mutations in the tumour suppressor gene PTEN have been implicated in two hamartoma syndromes that exhibit some clinical overlap, Cowden syndrome (CS) and Bannayan-Riley-Ruvalcaba syndrome (BRR). PTEN maps to 10q23 and encodes a dual specificity phosphatase, a substrate of which is phosphatidylinositol 3,4,5-triphosphate, a phospholipid in the phosphatidylinositol 3-kinase pathway. CS is characterized by multiple hamartomas and an increased risk of benign and malignant disease of the breast, thyroid and central nervous system, whilst the presence of cancer has not been formally documented in BRR. The partial clinical overlap in these two syndromes is exemplified by the hallmark features of BRR: macrocephaly and multiple lipomas, the latter of which occur in a minority of individuals with CS. Additional features observed in BRR, which may also occur in a minority of CS patients, include Hashimoto's thyroiditis, vascular malformations and mental retardation. Pigmented macules of the glans penis, delayed motor development and neonatal or infant onset are noted only in BRR. In this study, constitutive DNA samples from 43 BRR individuals comprising 16 sporadic and 27 familial cases, 11 of which were families with both CS and BRR, were screened for PTEN mutations. Mutations were identified in 26 of 43 (60%) BRR cases. Genotype-phenotype analyses within the BRR group suggested a number of correlations, including the association of PTEN mutation and cancer or breast fibroadenoma in any given CS, BRR or BRR/CS overlap family ( P = 0.014), and, in particular, truncating mutations were associated with the presence of cancer and breast fibroadenoma in a given family ( P = 0.024). Additionally, the presence of lipomas was correlated with the presence of PTEN mutation in BRR patients ( P = 0.028). In contrast to a prior report, no significant difference in mutation status was found in familial versus sporadic cases of BRR ( P = 0.113). Comparisons between BRR and a previously studied group of 37 CS families suggested an increased likelihood of identifying a germline PTEN mutation in families with either CS alone or both CS and BRR when compared with BRR alone ( P = 0.002). Among CS, BRR and BRR/CS overlap families that are PTEN mutation positive, the mutation spectra appear similar. Thus, PTEN mutation-positive CS and BRR may be different presentations of a single syndrome and, hence, both should receive equal attention with respect to cancer surveillance.

Proteus syndrome: diagnostic criteria, differential diagnosis, and patient evaluation

Proteus syndrome is a complex disorder comprising malformations and overgrowth of multiple tissues. The disorder is highly variable and appears to affect patients in a mosaic manner. This intrinsic variability has led to diagnostic confusion associated with a dearth of longitudinal data on the natural history of Proteus syndrome. To clarify some of these issues, a workshop on Proteus syndrome was held in March 1998 at the National Institutes of Health, and participants developed recommendations for diagnostic criteria, differential diagnosis, and guidelines for the evaluation of patients. This is a review of those recommendations.

Williams-Beuren syndrome: an update and review for the primary physician

Williams-Beuren syndrome is an autosomal dominant disorder resulting from a submicroscopic deletion of contiguous genes on the long arm of chromosome 7. It consists of a variety of hallmark physical features, which include distinctive facial characteristics, cardiac anomalies (of which the most common is supravalvular aortic stenosis), and occasional idiopathic hypercalcemia. The condition also includes a unique cognitive profile, with relative sparing of language and facial recognition skills against a background of mental retardation. This paper reviews the early history and clinical experience with this syndrome, how it unfolds from infancy through adulthood, and how it manifests in different organ systems. Evidence-based recommendations are then offered for the treatment of the specific developmental and medical issues that arise in patients with Williams syndrome.

Contribution of clinical teratologists and geneticists to the evaluation of the etiology of congenital malformations alleged to be caused by environmental agents: ionizing radiation, electromagnetic fields, microwaves, radionuclides, and ultrasound

Analysis of these six clinical problems demonstrates the value of a complete clinical evaluation of a child with congenital malformations by an experienced and well-trained physician who is familiar with the fields of developmental biology, teratology , epidemiology, and genetics. Too often, the entire emphasis is placed on epidemiological data that may be meager or insufficient for a rational conclusion when clinical findings that are readily available can provide definitive answers with regard to the etiology of a child's malformations or the merits of an environmental etiology.

Direct measurement of cerebrospinal fluid pressure through the cochlea in a congenitally deaf child with Mondini dysplasia undergoing cochlear implantation

OBJECTIVE

Perilymph/cerebrospinal fluid (CSF) "gushers" may occur at cochleostomy during cochlear implant surgery, particularly in patients with congenital cochlear duct malformation in which CSF in the internal auditory meatus is in direct communication with the perilymphatic space in the cochlea. The object of the study was to measure the pressure and flow of a CSF gusher at cochleostomy.

STUDY DESIGN

The design was a preoperative pressure measurement.

SETTING

The setting was a multidisciplinary cochlear implant program.

PATIENT

A 4-year-old girl with bilateral Mondini deformity undergoing cochlear implantation was studied.

INTERVENTION

A size 23 FG intravenous cannula was inserted into the cochlea and connected to a pediatric drip set to form an improvised manometer.

MAIN OUTCOME MEASURE

Intracochlear fluid pressure was measured at 14 cm H2O, equivalent to the normal CSF pressure that would be recorded in a child of this age at lumbar puncture. An indirect measurement of the likely size of the CSF/perilymph defect was made.

RESULTS

This technique may allow better assessment of the risk of postoperative CSF leakage and meningitis.

CONCLUSION

This simple technique of measuring the pressure in a perilymph gusher can be used to assess the need for careful sealing of the cochleostomy, to measure the reduction in pressure produced by head elevation or a spinal drain, and to assess the probable size of a defect in the lamina cribrosa.

A data-driven approach to the study of heterogeneity in idiopathic Parkinson's disease: identification of three distinct subtypes

Idiopathic Parkinson's disease (IPD) has been subclassified on the basis of predominant motor symptomatology, age at disease onset, depressive affect, and cognitive performance. However, subgroups are usually arbitrarily defined and not reliably based on qualitatively distinct neuropathology. We explored heterogeneity in IPD in a data-driven manner using comprehensive demographic, motor, mood, and cognitive information collected from 176 patients with IPD. Cluster analysis revealed three subgroups of patients at a disease duration of 5.6 years and two subgroups at 13.4 years. The subgroups may represent the clinical progression of three distinct subtypes of IPD. The "motor only" subtype was characterized by motor symptom progression in the absence of intellectual impairment. Equivalent motor symptom progression was shown by the "motor and cognitive" subtype which was accompanied by executive function deficits progressing to global cognitive impairment. The "rapid progression" subtype was characterized by an older age at disease onset and rapidly progressive motor and cognitive disability. There was no relationship between the motor and cognitive symptoms in any subtype of IPD. We conclude that the clinical heterogeneity of IPD is governed by distinct neuropathologic processes with independent etiologic influences.

The spectrum of mutations in UBE3A causing Angelman syndrome

Angelman syndrome (AS) is characterized by mental retardation, absence of speech, seizures and motor dysfunction. AS is caused by maternal deletions for chromosome 15q11-q13, paternal uniparental disomy (UPD), imprinting defects or loss-of-function mutations in the UBE3A locus which encodes E6-AP ubiquitin-protein ligase. The UBE3A gene is imprinted with paternal silencing in human brain and similar silencing of the Ube3a locus in Purkinje cells and hippocampal neurons in the mouse. We have sequenced the major coding exons for UBE3A in 56 index patients with a clinical diagnosis of AS and a normal DNA methylation pattern. The analysis identified disease-causing mutations in 17 of 56 patients (30%) including 13 truncating mutations, two missense mutations, one single amino acid deletion and one stop codon mutation predicting an elongated protein. Mutations were identified in six of eight families (75%) with more than one affected case, and in 11 of 47 isolated cases (23%); no mutation was found in one family with two siblings, one with a typical and one with an atypical phenotype. Mutations were de novo in nine of the 11 isolated cases. An amino acid polymorphism of threonine substituted for alanine at codon 178 was identified, and a 3 bp length polymorphism was found in the intron upstream of exon 8. In all informative cases, phenotypic expression was consistent with imprinting with a normal phenotype when a mutation was on the paternal chromosome and an AS phenotype when a mutation was on the maternal chromosome. Laboratory diagnosis and genetic counseling for AS are complex, and mutation analysis is valuable in clinically typical AS patients with a normal methylation analysis.

Syndromes associated with immunodeficiency

Immunodeficiency often has a genetic basis. Immune defects are the predominant manifestation in primary immunodeficiency disorders, and immune defects may also be associated with a number of other recognizable syndromes. There are 45 recognized primary immunodeficiency disorders, but immunodeficiency has been reported in 105 other syndromes. Abnormalities associated with these syndromes include growth deficiency (19 syndromes with disproportionate or proportionate short stature); specific organ system dysfunction (39 with gastrointestinal, dermatologic, or neurologic abnormalities); inborn errors of metabolism (17); miscellaneous anomalies (17); and chromosome anomalies (13). In most of these disorders, immunodeficiency is present in only a portion of the patients. However, in 49 syndromes, immunodeficiency is present in the vast majority. We review the clinical manifestations of each syndrome and delineate the associated immune defects. For most, the underlying mechanism linking the immune defect and other anomalies is unclear. Recognition of these conditions involving both the immune and other organ systems may facilitate accurate diagnosis and management, as well as yield information regarding genes critical for the development of the involved systems.

FG syndrome: report of three new families with linkage to Xq12-q22.1

FG syndrome is a rare X-linked recessive form of mental retardation, first described by Opitz and Kaveggia in 1974 in five related males with mental retardation, disproportionately large heads, imperforate anus, and congenital hypotonia. Partial agenesis of the corpus callosum was noted in at least one of the initial cases and has been seen in a number of subsequently-reported cases. The associated congenital hypotonia with joint hyperlaxity tends to progress to contractures with spasticity and unsteady gait in later life. The presence of subtle facial abnormalities and the characteristic behavior in midchildhood facilitate diagnosis at this age, particularly when there are other affected male relatives in the maternal family. Recently, Briault et al. [1997] mapped a gene for FG syndrome to the Xq12-q21.31 region. We describe three additional families (six additional patients) with FG syndrome on whom we have conducted linkage analysis. Our findings support the localization of a gene for the FG syndrome in Xq12-q21. In addition, we have noted skewed X-inactivation in carrier females, as well as new associated findings in affected males of sagittal craniosynostosis and split hand malformation.

Olanzapine in the treatment of hallucinosis in idiopathic Parkinson's disease: a cautionary note

BACKGROUND

Hallucinosis is a dopaminergic dose limiting complication of the treatment of idiopathic Parkinson's disease. Typical neuroleptic medications cannot be used for suppressing hallucinosis because the extrapyramidal side effects worsen parkinsonian motor control. Olanzapine is a novel atypical antipsychotic drug with few reported extrapyramidal side effects which may be more suitable for controlling hallucinosis in these patients.

METHODS

Olanzapine was given to five patients with idiopathic Parkinson's disease and the dosage was titrated until a clinically meaningful reduction in hallucinosis was achieved. The commercially available 5 mg, 7.5 mg and 10 mg tablets were used.

RESULTS

After an initial 9 days of treatment, hallucinosis frequency was significantly reduced, an effect which was maintained with continued treatment. However, during this early phase of treatment, parkinsonian motor disability increased, which resulted in two of the patients discontinuing medication.

CONCLUSIONS

Olanzapine is effective in the suppression of hallucinosis in patients with idiopathic Parkinson's disease but the currently available dose increments may result in an unacceptable exacerbation of motor disability.