Disruptive mutations in TANC2 define a neurodevelopmental syndrome associated with psychiatric disorders

Postsynaptic density (PSD) proteins have been implicated in the pathophysiology of neurodevelopmental and psychiatric disorders. Here, we present detailed clinical and genetic data for 20 patients with likely gene-disrupting mutations in TANC2-whose protein product interacts with multiple PSD proteins. Pediatric patients with disruptive mutations present with autism, intellectual disability, and delayed language and motor development. In addition to a variable degree of epilepsy and facial dysmorphism, we observe a pattern of more complex psychiatric dysfunction or behavioral problems in adult probands or carrier parents. Although this observation requires replication to establish statistical significance, it also suggests that mutations in this gene are associated with a variety of neuropsychiatric disorders consistent with its postsynaptic function. We find that TANC2 is expressed broadly in the human developing brain, especially in excitatory neurons and glial cells, but shows a more restricted pattern in Drosophila glial cells where its disruption affects behavioral outcomes.

Brain Morphometry and Psychobehavioural Measures in Autistic Low-Functioning Subjects

In the last two decades neurological research has significantly increased knowledge on the neuroanatomic bases of autism. Several autopsy and quantitative magnetic resonance imaging (MRI) studies have reported central nervous system (CNS) abnormalities which may underlie the social, language and cognitive dysfunction typical of the autistic disorder.

Despite the wealth of evidence that the “autistic brain” is different from normal in a number of structures, the relationship between the severity of the developmental impairment in autism and the degree of the brain abnormality remains unknown.

The aim of the present study is to correlate the areas of some brain regions, as calculated on the basis of MRI morphometry, with the Childhood Autism Rating Scale (CARS) and with the Psychoeducational Profile Revised (PEP-R) scores in a group of 22 autistic mentally retarded male subjects.

Seizures and EEG pattern in the 22q13.3 deletion syndrome: clinical report of six Italian cases

PURPOSE

The 22q13.3 deletion syndrome, also known as Phelan-McDermid syndrome, is a rare genetic disorder characterized by hypotonia, severely impaired development of speech and language, autistic-like behaviour, and minor dysmorphic features. Neurologic problems may include seizures of different types, such as febrile, generalized tonic-clonic, focal, and absence seizures. No peculiar EEG features have been associated with 22q13 deletion syndrome to date. In order to verify if a peculiar clinical and EEG pattern is present in 22q13.3 deletion syndrome, we studied six Italian patients with this chromosome abnormality.

METHOD

Array CGH analysis was carried out in the six subjects (1 male, 5 females, age range 11-30 years, median 19.5). They underwent a complete general and neurologic examinations. The EEG study consisted of at least one awake and one nap-sleep video-EEG recordings and evaluation of other EEGs performed elsewhere.

RESULTS

Three subjects suffered from myoclonic or generalized tonic-clonic seizures with a rather benign course; all showed multifocal paroxysmal abnormalities on EEG recording, predominant over the frontal-temporal regions, activated during sleep.

CONCLUSION

22q13.3 deletion syndrome seems to be associated, at least in a subgroup of patients, with a peculiar clinical and EEG pattern, characterized by a childhood epilepsy with a rather benign evolution and with multifocal paroxysmal EEG abnormalities activated by sleep.

An atypical patient with Cowden syndrome and PTEN gene mutation presenting with cortical malformation and focal epilepsy

We report the case of a girl with Cowden syndrome (CS) presenting with unilateral perisylvian dysplasia and with drug resistant focal seizures carrying a novel missense mutation 385G>A (G129R) in the PTEN gene. CS has been rarely reported in association with a cortical malformation or epilepsy. These cases suggest that cortical dysplasia needs to be suspected when a CS patient presents with drug-resistant seizures.

CDKL5 mutations in boys with severe encephalopathy and early-onset intractable epilepsy

OBJECTIVE

To search for CDKL5 gene mutations in boys presenting with severe early-onset encephalopathy and intractable epilepsy, a clinical picture very similar to that already described in girls with CDKL5 mutations.

METHODS

Eight boys (age range 3-16 years, mean age 8.5 years, SD 4.38) with severe or profound mental retardation and early-onset intractable seizures were selected for CDKL5 gene mutation screening by denaturing high-performance liquid chromatography analysis.

RESULTS

We found three unrelated boys carrying three different missense mutations of the CDKL5 gene: c.872G>A (p.C291Y), c.863C>T (p.T288I), and c.533G>C (p.R178P). They presented early-onset, polymorphous, and drug-resistant seizures, mostly myoclonic and tonic or spasms. EEG showed epileptiform abnormalities which were multifocal during wakefulness, and pseudoperiodic bisynchronous during sleep.

CONCLUSIONS

This study describes three boys carrying CDKL5 missense mutations and their detailed clinical and EEG data, and indicates that CDKL5 gene mutations may represent a cause of severe or profound mental retardation and early-onset intractable seizures, also in boys. Screening for CDKL5 mutations is strongly recommended in individuals with these clinical features.

Clinical correlates of brain morphometric features of subjects with low-functioning autistic disorder

Numerous neuropathologic and imaging studies have reported different structural abnormalities in the brains of autistic subjects. However, whether or not the degree of brain abnormality is correlated with the severity of developmental impairment in autistic disorder is still unknown. The midsagittal area of the cerebrum, corpus callosum, midbrain, cerebellar vermis, and vermal lobules VI and VII was measured by means of magnetic resonance imaging in 22 boys with low-functioning autistic disorder and in 11 age-matched normal controls. Morphometric measures were statistically compared between groups and correlated with age and scores on the Psychoeducational Profile-Revised and the Childhood Autism Rating Scale. A significant negative correlation was found between midsagittal area of the cerebrum and age in patients with autistic disorder, and a positive correlation was found between the midsagittal area of the midbrain and some subscales of the Psychoeducational Profile-Revised.

Sleep in subjects with autistic disorder: a neurophysiological and psychological study

Polysomnography (EOG, EEG, EMG) was carried out in 17 male children and adolescents with autistic disorder, in seven patients with mental retardation and fragile X syndrome, and in five age- and sex-matched normal male subjects. Density of rapid eye movements was not significantly different in the three groups of subjects; however, some sleep parameters such as time in bed, sleep period time, and total sleep time were significantly lower in subjects with autistic disorder than in normal controls; moreover, patients with autistic disorder showed values of sleep period time, first REM latency and percent (%) sleep stage 1 lower than those of patients with fragile X syndrome with mental retardation. Density of muscle twitches was significantly higher in patients with autistic disorder than in normal controls. In contrast only minor differences were observed between patients with autistic disorder and those with fragile X syndrome with mental retardation. Furthermore, some psychoeducational profile-revised items such as perception and eye-hand coordination, showed significant correlation with some sleep parameters (time in bed, sleep latency, stage shifts, first REM latency and wakefulness after sleep onset). Childhood Autism Rating Scale (CARS) scores to visual response and non-verbal communication showed significant correlation with some tonic sleep parameters, such as sleep period time, wakefulness after sleep onset, and total sleep time. Relating to people and activity level items were found to be significantly correlated with rapid eye movement density. Our results suggest the existence of a sleep pattern in autistic patients different from that observed in subjects with mental retardation and from that of normal controls. In addition, these findings indicate that sleep parameters in these patients are correlated with some psychological indices generally used for the diagnosis of autistic disorder; for this reason, polysomnographies might be useful in the comprehension of the neurophysiological mechanisms underlying this condition.

Familial cortical tremor, epilepsy, and mental retardation: a distinct clinical entity?

OBJECTIVE

To describe a European family with cortical tremor, epilepsy, and mental retardation, the pedigree of which indicates an autosomal dominant inheritance of the disease.

DESIGN

Clinical, laboratory, neurophysiological, and neuroimaging data were studied.

SETTING

Institute for research on mental retardation.

PATIENTS

Two siblings (aged 25 and 28 years) and their 49-year-old mother had postural and action tremor, seizures, and mental retardation. Only tremor was present in the maternal grandmother (aged 68 years). The electroencephalogram showed diffuse spike-and-wave complexes and/or posterior spikes, and a photoparoxysmal response in the 4 subjects. The typical electrophysiologic features of cortical reflex myoclonus, such as giant somatosensory evoked potentials, enhancement of the C-reflex, and jerk-locked premyoclonus spikes, were found in all patients.

CONCLUSION

This syndrome may represent a specific form of familial cortical tremor with a benign form of epilepsy and a new genetic model of cortical hyperexcitability inherited with an autosomal dominant mechanism.