Phelan-McDermid syndrome (PMS) is characterized by a variety of clinical symptoms with heterogeneous degrees of severity, including intellectual disability (ID), absent or delayed speech, and autism spectrum disorders (ASD). It results from a deletion of the distal part of chromosome 22q13 that in most cases includes the SHANK3 gene. SHANK3 is considered a major gene for PMS, but the factors that modulate the severity of the syndrome remain largely unknown. In this study, we investigated 85 patients with different 22q13 rearrangements (78 deletions and 7 duplications). We first explored the clinical features associated with PMS, and provide evidence for frequent corpus callosum abnormalities in 28% of 35 patients with brain imaging data. We then mapped several candidate genomic regions at the 22q13 region associated with high risk of clinical features, and suggest a second locus at 22q13 associated with absence of speech. Finally, in some cases, we identified additional clinically relevant copy-number variants (CNVs) at loci associated with ASD, such as 16p11.2 and 15q11q13, which could modulate the severity of the syndrome. We also report an inherited SHANK3 deletion transmitted to five affected daughters by a mother without ID nor ASD, suggesting that some individuals could compensate for such mutations. In summary, we shed light on the genotype-phenotype relationship of patients with PMS, a step towards the identification of compensatory mechanisms for a better prognosis and possibly treatments of patients with neurodevelopmental disorders.
This is the largest cohort of prenatal del22q11.2 diagnoses. As in postnatally diagnosed cases, HDs were the most frequently observed abnormalities. However, thymus and kidney abnormalities and polyhydramnios should also be screened for in the prenatal diagnosis of del22q11.2. Only the time of diagnosis appeared to be strongly associated with the pregnancy outcome: the earlier the diagnosis, the higher the TOP rate.
Impaired oxidative stress defense has been reported in blood of both drug-naïve and antipsychotic-treated patients suffering from schizophrenic psychosis, indicating the involvement of free radical metabolism in the pathogenetic processes of schizophrenia. In this study, the concentrations of two isoenzymes of superoxide dismutase (SOD), Cu, Zn- and MnSOD, were determined with ELISA in various cortical (frontal, parietal, temporal and occipital cortex) and subcortical areas (putamen, caudate nucleus, thalamus, and substantia innominata) of post-mortem brain tissue from patients diagnosed with a schizophrenia spectrum disorder and compared with those of controls. Post-mortem brain tissue from individuals without neuropsychiatric disorders served for control. Cu, Zn- and MnSOD levels were significantly increased in frontal cortex and substantia innominata of the index group, respectively. In all other areas both types of SOD remained virtually unchanged. Detection of SOD changes in the brain supports previous reports of alterations of antioxidant indices in blood cells of patients with schizophrenia and suggests a specific neuroanatomical distribution pattern of oxidative stress processes possibly related to the pathophysiology of schizophrenia.
Hennekam syndrome is a rare autosomal recessive syndrome which was described for the first time in 1989. Here, we present a girl with intestinal lymphangiectasia, severe lymphedema of limbs, seizures, mild mental retardation, and facial anomalies consistent with the diagnosis of Hennekam syndrome. In addition, she had an ectopic kidney and craniosynostosis of the coronal suture, 2 manifestations not previously reported in this syndrome. While the molecular basis of Hennekam syndrome remains, as yet, unknown, this report illustrates its variable clinical expression.
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