Disruption of the non-canonical Wnt gene PRICKLE2 leads to autism-like behaviors with evidence for hippocampal synaptic dysfunction.

Autism spectrum disorders (ASDs) have been suggested to arise from abnormalities in the canonical and non-canonical Wnt signaling pathways. However, a direct connection between a human variant in a Wnt pathway gene and ASD-relevant brain pathology has not been established. Prickle2 (Pk2) is a post-synaptic non-canonical Wnt signaling protein shown to interact with post-synaptic density 95 (PSD-95). Here, we show that mice with disruption in Prickle2 display behavioral abnormalities including altered social interaction, learning abnormalities and behavioral inflexibility. Prickle2 disruption in mouse hippocampal neurons led to reductions in dendrite branching, synapse number and PSD size. Consistent with these findings, Prickle2 null neurons show decreased frequency and size of spontaneous miniature synaptic currents. These behavioral and physiological abnormalities in Prickle2 disrupted mice are consistent with ASD-like phenotypes present in other mouse models of ASDs. In 384 individuals with autism, we identified two with distinct, heterozygous, rare, non-synonymous PRICKLE2 variants (p.E8Q and p.V153I) that were shared by their affected siblings and inherited paternally. Unlike wild-type PRICKLE2, the PRICKLE2 variants found in ASD patients exhibit deficits in morphological and electrophysiological assays. These data suggest that these PRICKLE2 variants cause a critical loss of PRICKLE2 function. The data presented here provide new insight into the biological roles of Prickle2, its behavioral importance, and suggest disruptions in non-canonical Wnt genes such as PRICKLE2 may contribute to synaptic abnormalities underlying ASDs.

Mutations in the CCN gene family member WISP3 cause progressive pseudorheumatoid dysplasia.

Members of the CCN (for CTGF, cyr61/cef10, nov) gene family encode cysteine-rich secreted proteins with roles in cell growth and differentiation. Cell-specific and tissue-specific differences in the expression and function of different CCN family members suggest they have non-redundant roles. Using a positional-candidate approach, we found that mutations in the CCN family member WISP3 are associated with the autosomal recessive skeletal disorder progressive pseudorheumatoid dysplasia (PPD; MIM 208230). PPD is an autosomal recessive disorder that may be initially misdiagnosed as juvenile rheumatoid arthritis. Its population incidence has been estimated at 1 per million in the United Kingdom, but it is likely to be higher in the Middle East and Gulf States. Affected individuals are asymptomatic in early childhood. Signs and symptoms of disease typically develop between three and eight years of age. Clinically and radiographically, patients experience continued cartilage loss and destructive bone changes as they age, in several instances necessitating joint replacement surgery by the third decade of life. Extraskeletal manifestations have not been reported in PPD. Cartilage appears to be the primary affected tissue, and in one patient, a biopsy of the iliac crest revealed abnormal nests of chondrocytes and loss of normal cell columnar organization in growth zones. We have identified nine different WISP3 mutations in unrelated, affected individuals, indicating that the gene is essential for normal post-natal skeletal growth and cartilage homeostasis.

Homozygous mutations in LPIN2 are responsible for the syndrome of chronic recurrent multifocal osteomyelitis and congenital dyserythropoietic anaemia (Majeed syndrome).

BACKGROUND: Majeed syndrome is an autosomal recessive, autoinflammatory disorder characterised by chronic recurrent multifocal osteomyelitis and congenital dyserythropoietic anaemia. The objectives of this study were to map, identify, and characterise the Majeed syndrome causal gene and to speculate on its function and role in skin and bone inflammation. METHODS: Six individuals with Majeed syndrome from two unrelated families were identified for this study. Homozygosity mapping and parametric linkage analysis were employed for the localisation of the gene responsible for Majeed syndrome. Direct sequencing was utilised for the identification of mutations within the genes contained in the region of linkage. Expression studies and in silico characterisation of the identified causal gene and its protein were carried out. RESULTS: The phenotype of Majeed syndrome includes inflammation of the bone and skin, recurrent fevers, and dyserythropoietic anaemia. The clinical picture of the six affected individuals is briefly reviewed. The gene was mapped to a 5.5 cM interval (1.8 Mb) on chromosome 18p. Examination of genes in this interval led to the identification of homozygous mutations in LPIN2 in affected individuals from the two families. LPIN2 was found to be expressed in almost all tissues. The function of LPIN2 and its role in inflammation remains unknown. CONCLUSIONS: We conclude that homozygous mutations in LPIN2 result in Majeed syndrome. Understanding the aberrant immune response in this condition will shed light on the aetiology of other inflammatory disorders of multifactorial aetiology including isolated chronic recurrent multifocal osteomyelitis, Sweet syndrome, and psoriasis.

Assignment of gene responsible for progressive pseudorheumatoid dysplasia to chromosome 6 and examination of COL10A1 as candidate gene.

Progressive pseudorheumatoid dysplasia is an autosomal recessive skeletal dysplasia with radiographic changes in the spine similar to Spondyleopiphyseal dysplasia tarda and clinical, though not radiographic resemblance to rheumatoid arthritis. About two-thirds of the reported patients are of Arabic and Mediterranean origin which reflects the relative high incidence in this population. We performed homozygosity mapping utilising the DNA pooling approach to map progressive pseudorheumatoid dysplasia to a chromosomal region on the long arm of chromosome 6. We examined a possible candidate gene in the same region of linkage, namely COL10A1, for alterations in this disorder. We did not identify any mutations in our family, but did not totally exclude COL10A1 gene from being the disease-causing gene.

Autosomal recessive lamellar ichthyosis and acute lymphoblastic leukemia.

Autosomal recessive lamellar ichthyosis (ARLI) is a congenital disorder of keratinization, the gene of which has been mapped to chromosome 14q11. This band is also the breakpoint in various chromosomal rearrangements in T cell acute lymphoblastic leukemia (ALL). We describe a patient with ARLI who developed ALL at the age of 2.5 years. High resolution banding showed no abnormality or rearrangement involving chromosome 14. To our knowledge, this is the first description of the occurrence of the two conditions in one patient.

Familial Mediterranean fever in children: the expanded clinical profile.

The clinical picture of familial Mediterranean fever (FMF) has been appreciably expanded in the last 10 years. Over 8 years, we studied the expanded clinical profile of FMF in 476 children. Of these, 81% had abdominal pain, 41% chest pain, 42% arthritis, 12% severe myalgia, 12% skin manifestations, 4% scrotal swelling, 3% recurrent episodic fever, and one child (0.2%) developed recurrent hyperbilirubinaemia. Two (0.4%) children developed renal complications which were reversed by colchicine; however of 19 probands, 36 family members suffered from chronic renal failure. Our study indicates a familial predisposition to nephropathy in certain families with FMF. This study is the first to report the expanded clinical profile of FMF in a large group of Arab children, giving an opportunity to compare the findings with those in children with FMF in other ethnic groups, and to help in the study of genotype-phenotype correlation.

Fine mapping of progressive pseudorheumatoid dysplasia: a tool for heterozygote identification.

Progressive pseudorheumatoid dysplasia is a skeletal genetic disorder affecting primarily the articular cartilage, causing joint stiffness and leading to a crippling status. More than two-thirds of the reported patients belong to Arab and Mediterranean populations. The disease locus has been mapped to chromosome 6q22 in a region of 12.9 cM using a Jordanian family. We examined two additional families, one Jordanian and one Palestinian, to test for homogeneity of the disorder and the presence of a common haplotype, to fine map the disorder, and to use all the information to derive a tool for heterozygote identification. The two families showed linkage to the same previously reported locus, thus suggesting homogeneity, but they did not share a common haplotype. They also provided information that refined the genetic region for the disease locus to 2.1 cM with three microsatellite markers. The absence of a common haplotype indicates that no common ancestor mutations were inherited by our patients. Genotyping for the three-marker haplotype showed that it can be used as a heterozygote identification tool.

Epidermal nevus syndrome: subgroup with neuronal migration defects.

Epidermal nevus syndrome is one of the sporadic congenital hamartoses in which neurologic abnormalities have been frequently reported. We report two cases with severe primary brain involvement, seizures, mental retardation, and facial hemihypertrophy. We emphasize the superiority of magnetic resonance imaging over other radiographic studies in outlining the primary central nervous system anomalies associated with this syndrome. Although attempts were made to distinguish between several variants of epidermal nevus syndrome, it is clear that these are one entity. Proteus syndrome, encephalocraniocutaneous lipomatosis, and epidermal nevus syndrome have several overlapping phenotypic features. We suggest that they represent a phenotypic continuum, which in turn suggests a common pathogenetic process. While the cause of these syndromes is unknown, observations point to a somatic mutation leading to variable patterns of mosaicism.

A clinical study of a large inbred kindred with pure familial spastic paraplegia.

BACKGROUND AND OBJECTIVES: Spastic paraplegia, an uncommon neurodegenerative disorder with phenotypic and genotypic heterogeneity, is mainly characterized by progressive weakness and spasticity of the lower limbs. We here present a large inbred family with pure familial spastic paraplegia outlining the clinical picture, the age at onset and the possible mode of inheritance. METHODS: This family was ascertained through two probands after which we structured an extended 10 generation pedigree. We examined 43 available family members to identify affected individuals based on fixed criteria. The clinical presentation and phenotypic specifics of this disease were studied in the affected members. We analyzed the possible mode of inheritance and the age at onset in this family. RESULTS: This 10 generation family reported about 50 affected individuals distributed over 5 consecutive generations. We identified 13 affected individuals out of the examined 43 and five individuals were classified as probably affected. We noticed the clinical specifics of this disorder in this family and identified some unique features not described in previous reports. DISCUSSION AND CONCLUSION: The mode of inheritance is either autosomal recessive or autosomal dominant with incomplete penetrance or variable expression of the age at onset. The age at onset seems to decrease with successive generations, either due to a true anticipatory phenomenon or to increased awareness. The unique features of this disorder in this family are discussed.

Risk factors for childhood epilepsy: a case-control study from Irbid, Jordan.

OBJECTIVE: The goal of this case-control study is to identify the significance of certain risk factors for epilepsy in a population of epileptic children in Northern Jordan. The risk factors examined are febrile convulsions, head trauma, central nervous system infections, abnormal perinatal history, family history and parental consanguinity. METHODOLOGY: We designed a case-control study for patients attending the outpatient neurology clinic of Princess Rahma Teaching Hospital in Irbid, Jordan during a 7-month period. Controls were selected, matched for age and sex, from a group of non-epileptic patients attending the general paediatrics outpatient clinic in the same hospital and during the same period. Data about the investigated risk factors were obtained by personal interview and review of the medical records and were analysed statistically for significance. RESULTS: The total number of participants was 200 patients and controls each. History of febrile convulsions, head trauma, abnormal perinatal history and family history showed a statistically significant increase risk for developing epilepsy. Central nervous system infections and parental consanguinity did not add to the risk of developing epilepsy. CONCLUSION: Positive family history for epilepsy, head trauma, febrile convulsions and abnormal perinatal history were shown to have a statistically significant association with epilepsy in patients attending Princess Rahma Teaching Hospital in Northern Jordan. Although consanguinity is widely practised in Jordan, it appears that it does not increase the risk of epilepsy probably due to the small contribution of monogenic recessive epilepsies to the population with epilepsy.

Familial Mediterranean Fever.

Familial Mediterranean Fever is a genetic disorder frequently diagnosed among the Arabs. It is also prevalent among Jews, Armenians and Turks. The clinical picture consists of febrile and painful attacks that differ in quality across patients and even within the same patient. There may be accompanying joint pain, chest pain, skin manifestations and other findings, and amyloidosis may occur in some patients as a complication. The primary treatment is Colchicine, which decreases the frequency of the attacks and prevents the occurrence of amyloidosis. The gene responsible for Familial Mediterranean Fever, MEFV, has been mapped and cloned and mutations were identified within its coding sequence. It encodes a protein that is expected to be a down regulator of inflammation. The spectrum of mutations in the Arabic population is partially studied. There are still several issues to be solved before we fully understand the disorder, and to enable us to confront it and decrease the morbidity and mortality inflicted by it.

Craniofacial anthropometric measurements in a population of normal Jordanian newborns.

Anthropometric measurements provide quantitative values for qualitative descriptions, thus playing an important role in the evaluation of individuals with dysmorphic features for the identification of patterns of dysmorphism. Normative standard values and curves are needed for the meaningful interpretation of individual measurements. The available normative standards vary mainly due to differences in the populations studied. We obtained 13 different craniofacial anthropometric measurements on 158 newborns from Jordan within the first 24 hours of birth. We excluded few newborns for selected measurements based on preset exclusion criteria. We calculated means and standard deviations and constructed standard curves for each measurement. We here present the clinicians in our country, and the surrounding countries as well, with a set of reference values and curves and a guide to be used in the evaluation of newborns with dysmorphism.

Transient improvement of congenital lactic acidosis in a male infant with pyruvate decarboxylase deficiency treated with dichloroacetate.

A comatose male newborn infant with congenital lactic acidosis caused by pyruvate decarboxylase deficiency was treated with dichloroacetate (DCA), which stimulated an 88% drop in serum lactate concentration and reversed his coma. The response to DCA was temporary and the lactic acidosis worsened until his death, but DCA may confer more lasting benefit in less severely affected infants.

Familial disorder of sex determination in seven individuals from three related sibships.

In humans, the sex of an individual is determined by the Y-chromosome-related SRY gene, which causes the differentiation of the undifferentiated gonads into testicular tissue. True hermaphrodites without a Y chromosome and XX males represent a sex determination error in which testicular tissue develops despite the absence of the SRY gene. Familial forms of XX true hermaphrodites and XX males exist in the literature, which also contains the two forms co-existing in the same family. In this report, we present a large family with seven affected individuals with phenotypes ranging from XX male to XX true hermaphrodite with predominance of female characteristics. We suggest that XX maleness and XX true hermaphroditism represent a continuum of the same disorder. We speculate on the mode of inheritance of this disorder in this particular family.