X-Linked Hydrocephalus with New L1CAM Pathogenic Variants: Review of the Most Prevalent Molecular and Phenotypic Features.

Introduction: The underlying molecular defects of congenital hydrocephalus are heterogeneous and many isolated forms of hydrocephalus remain unsolved at the molecular level. Congenital hydrocephalus in males associated with agenesis of the corpus callosum is a notable characteristic of L1CAM gene which is by far the most common genetic etiology of congenital hydrocephalus. Methods and Results: Sequencing of the L1CAM gene on 25 male patients/fetuses who had been presented with hydrocephalus revealed 6 patients and two fetuses with different hemizygous pathogenic variants. Our study identified 4 novel variants and 4 previously reported. The detection rate was 32%, and all the variants were shown to be maternally inherited. Nonsense variants were detected in 3 patients, while missense variants were detected in 2 patients. Frameshift, silent, and splicing variant, each was detected in 1 patient. The clinical manifestations of the patients are in line with those frequently observed including communicating hydrocephalus and agenesis of the corpus callosum. Moreover, rippled ventricles with subdural collection and asymmetry of ventricles after shunt operation were seen in 1 patient and 2 patients, respectively. In addition, abnormal basal ganglia were found in 4 patients which seems to be an additional distinct new finding. We also describe a patient with novel nonsense variant with the rare association of Hirschsprung's disease. This patient displayed additionally multiple porencephalic cysts and encephalomalacia secondary to hemorrhage due to repeated infections after shunt operation. The patients with the missense variants showed long survival, while those with truncating variants showed poor prognosis. Conclusion: This report adds knowledge of novel pathogenic variants to the L1CAM variant database. Furthermore, we evaluated the clinical and imaging data of these patients.

Micro and Martsolf syndromes in 34 new patients: Refining the phenotypic spectrum and further molecular insights.

Micro and Martsolf syndromes are rare clinically and genetically overlapping disorders caused by mutations in RAB3GAP1, RAB3GAP2, RAB18 and TBC1D20 genes. We describe 34 new patients, 27 with Micro and seven with Martsolf. Patients presented with the characteristic clinical manifestations of the two syndromes, including postnatal microcephaly, congenital cataracts, microphthalmia, optic atrophy, spasticity and intellectual disability. Brain imaging showed in the majority of cases polymicrogyria, thin corpus callosum, cortical atrophy, and white matter dysmyelination. Unusual additional findings were pectus excavatum (four patients), pectus carinatum (three patients), congenital heart disease (three patients) and bilateral calcification in basal ganglia (one patient). Mutational analysis of RAB3GAP1 and RAB3GAP2 revealed 21 mutations, including 14 novel variants. RAB3GAP1 mutations were identified in 22 patients with Micro, including a deletion of the entire gene in one patient. On the other hand, RAB3GAP2 mutations were identified in two patients with Micro and all Martsolf patients. Moreover, exome sequencing unraveled a TBC1D20 mutation in an additional family with Micro syndrome. Our results expand the phenotypic and mutational spectrum associated with Micro and Martsolf syndromes. Due to the overlapped severities and genetic basis of both syndromes, we suggest to be comprehended as one entity "Micro/Martsolf spectrum" or "RAB18 deficiency."

Microcephalic osteodysplastic primordial dwarfism type II: Additional nine patients with implications on phenotype and genotype correlation.

PCNT encodes a large coiled- protein localizing to pericentriolar material and is associated with microcephalic osteodysplastic primordial dwarfism type II syndrome (MOPD II). We report our experience of nine new patients from seven unrelated consanguineous Egyptian families with the distinctive clinical features of MOPD II in whom a customized NGS panel showed homozygous truncating variants of PCNT. The NGS panel results were validated thereafter using Sanger sequencing revealing three previously reported and three novel PCNT pathogenic variants. The core phenotype appeared homogeneous to what had been reported before although patients differed in the severity showing inter and intra familial variability. The orodental pattern showed atrophic alveolar ridge (five patients), rootless tooth (four patients), tooth agenesis (three patients), and malformed tooth (three patients). In addition, mesiodens was a novel finding found in one patient. The novel c.9394-1G>T variant was found in two sibs who had tooth agenesis. CNS anomalies with possible vascular sequelae were documented in two male patients (22.2%). Simplified gyral pattern with poor development of the frontal horns of lateral ventricles was seen in four patients and mild thinning of the corpus callosum in two patients. Unilateral coronal craniosynstosis was noted in one patient and thick but short corpus callosum was an unusual finding noted in another. The later has not been reported before. Our results refine the clinical, neuroradiological, and orodental features and expand the molecular spectrum of MOPD II.

Molecular and phenotypic spectrum of ASPM-related primary microcephaly: Identification of eight novel mutations.

Autosomal recessive primary microcephaly (MCPH) is an abnormal proliferation of neurons during brain development that leads to a small brain size but architecturally normal in most instances. Mutations in the ASPM gene have been identified to be the most prevalent. Thirty-seven patients from 30 unrelated families with a clinical diagnosis of MCPH were enrolled in this study. Screening of ASPM gene mutations was performed by targeted linkage analysis followed by direct sequencing. Thirteen protein truncating mutations of the ASPM were identified in 15 families (50%), eight of which were novel mutations. The mutations detected were eight nonsense, four frameshift, and one splice site. Two of these mutations (p.R1327* and p.R3181*) were recurrent and shared similar haplotypes suggesting founder effect. Patients with ASPM mutations had mild to severe intellectual disability and variable degrees of simplified gyral pattern and small frontal lobe. In addition, hypoplasia of corpus callosum (18 patients), mildly small cerebellar vermis (10 patients), and relatively small pons (13 patients) were found in 85.7%, 47.6%, and 61.9%, respectively. Furthermore, one patient had porencephaly and another had a small midline cyst. Epilepsy was documented in two patients (9.5%). Non-neurologic abnormalities consisted of growth retardation (four patients), and co-incidental association of oculo-cutaneous albinism (one patient). Our study expands the mutation spectrum of ASPM. Moreover, the simplified gyral pattern and small frontal lobe together with hypoplastic corpus callosum, small cerebellum and pons enable ASPM mutated patients to be distinguished. © 2016 Wiley Periodicals, Inc.

C242T polymorphism of NADPH oxidase p22phox gene reduces the risk of coronary artery disease in a random sample of Egyptian population.

The p22phox protein subunit is essential for NADPH oxidase activity. The prevalence of C242T variants of p22phox gene was studied in 101 healthy Egyptian controls and 104 acute myocardial infarction (AMI) Egyptian patients. Contribution of oxidative stress, represented by serum oxidized-LDL (ox-LDL), in development of AMI was also examined and correlated with C242T gene variants. Genotyping and ox-LDL were assessed by PCR-RFLP and ELISA. Results showed that wild type CC genotype is prevalent in 27 % of controls; CT and TT are in 72 and 1 %. In patients, the distribution was 40.2, 59.8 and 0 % for CC, CT and TT; respectively, showing a significant difference (p = 0.0259). Serum ox-LDL levels were higher in patients than controls (p ≤ 0.0001). Subjects having CT genotype had lower levels of ox-LDL than CC genotype (p ≤ 0.005). C242T polymorphism of p22phox gene of NADPH oxidase is a novel genetic marker associated with reduced susceptibility to AMI.

Relationship between Biochemical Bone Markers and Bone Mineral Density in Patients with Phenylketonuria under Restricted Diet.

OBJECTIVE: Most of phenylketonuria (PKU) develops bone turnover impairment and low bone mineral density (BMD). Measurements of BMD reflect only bone mineral status but not the dynamics of bone turnover. Bone markers are a noninvasive tool useful for the assessment of bone formation and bone resorption processes. Our study was to assess the levels of bone markers in PKU in order to select a screen marker and detect the most specific marker which can be combined with BMD for appropriate follow up. METHODS: Thirty three classic PKU patients were studied. BMD and bone mineral content (BMC) were measured. Total alkaline phosphatase (ALP), osteocalcin (OC) and carboxy-terminal propeptide of type I collagen (CICP), osteoprotegerin (OPG), receptor activator of nuclear factor κß ligand (RANKL) and Deoxypyridinoline (DPD) were measured. Findings : Nineteen (57.6%) male and fourteen (42.4 %) female PKU patients were involved in the current study. Their mean age was 8.4±4.6 yrs and the age range 3-19 yrs. The control group consisted of twenty two (52.4%) males and twenty (47.6%) females. Their mean age was 8.5±3.3 yrs and th age range 2-17 yrs. Using the Z score values, there was a significant decrease of total BMC (TBMC-Z), BMD of the femoral neck BMD-FN-Z, BMD of lumbar vertebrae (BMD-L-Z), BMD-FN and DPD while RANKL increased. There was a negative correlation between CICP and TBMC and between CICP and BMD-L in these patients. Also, a negative correlation between ALP and TBMC and between ALP and BMD-L was observed. It was concluded that the ALP provides a good impression of the new bone formation in the PKU patients and it has a highly significant negative correlation with the many parameters of the bone mineral status beside the wide availability of inexpensive and simple methods. So a screening test and/or follow up for the PKU patients using ALP would be available. Once the level of ALP decrease is detected, one can combine it with BMD to explore the bone mineral status and with specific bone markers (OC, RANKL and DBD), to verify the dynamics of bone turnover. CONCLUSION: This schedule will reduce the risk of exposure of these patients to the risk hazards of DXA and limit its use only to a limited number of the highly suspected cases.

Profound microcephaly, primordial dwarfism with developmental brain malformations: a new syndrome.

We describe two sibs with a lethal form of profound congenital microcephaly, intrauterine and postnatal growth retardation, subtle skeletal changes, and poorly developed brain. The sibs had striking absent cranial vault with sloping of the forehead, large beaked nose, relatively large ears, and mandibular micro-retrognathia. Brain magnetic resonance imaging (MRI) revealed extremely simplified gyral pattern, large interhemispheric cyst and agenesis of corpus callosum, abnormally shaped hippocampus, and proportionately affected cerebellum and brainstem. In addition, fundus examination showed foveal hypoplasia with optic nerve atrophy. No abnormalities of the internal organs were found. This profound form of microcephaly was identified at 17 weeks gestation by ultrasound and fetal brain MRI helped in characterizing the developmental brain malformations in the second sib. Molecular analysis excluded mutations in potentially related genes such as RNU4ATAC, SLC25A19, and ASPM. These clinical and imaging findings are unlike that of any recognized severe forms of microcephaly which is believed to be a new microcephalic primordial dwarfism (MPD) with developmental brain malformations with most probably autosomal recessive inheritance based on consanguinity and similarly affected male and female sibs.

A homozygous mutation in RNU4ATAC as a cause of microcephalic osteodysplastic primordial dwarfism type I (MOPD I) with associated pigmentary disorder.

The designation microcephalic osteodysplastic primordial dwarfism (MOPD) refers to a group of autosomal recessive disorders, comprising microcephaly, growth retardation, and a skeletal dysplasia. The different types of MOPD have been delineated on the basis of clinical, radiological, and genetic criteria. We describe two brothers, born to healthy, consanguineous parents, with intrauterine and postnatal growth retardation, microcephaly with abnormal gyral pattern and partial agenesis of corpus callosum, and skeletal anomalies reminiscent of those described in MOPD type I. This was confirmed by the identification of the homozygous g.55G > A mutation of RNU4ATAC encoding U4atac snRNA. The sibs had yellowish-gray hair, fair skin, and deficient retinal pigmentation. Skin biopsy showed abnormal melanin function but OCA genes were normal. The older sib had an intracranial hemorrhage at 1 week after birth, the younger developed chilblains-like lesions at the age 2½ years old but analysis of the SAMHD1 and TREX1 genes did not show any mutations. To the best of our knowledge, vasculopathy and pigmentary disorders have not been reported in MOPD I.

A long-term study of bone mineral density in patients with phenylketonuria under diet therapy.

INTRODUCTION: Dietary control of classic phenylketonuria (PKU) needs restriction of natural proteins; adequate protein intake is achieved by adding low phenylalanine (phe) formulae. The adequacy of this diet for normal bone mineralization had not been sufficiently evaluated. Our aim was to evaluate and follow up bone mineral density (BMD) in children and adolescents with PKU within a 2-year time interval to assess the adequacy of a phenylalanine restricted diet for bone mineralization and to search for a possible relationship between BMD, dietary control and blood phenylalanine (phe) concentrations. MATERIAL AND METHODS: Thirty-two patients with classic PKU (3-19 years) were evaluated for their bone mineral status using dual energy X-ray absorptiometry (DEXA) both at the beginning (baseline) and the end (follow-up) of the study. RESULTS: Low BMD was detected in 31.25% at the start and in 6.25% of patients after 2 years follows-up. No relationship was found between BMD and the duration of diet compliance and phe level as well. CONCLUSIONS: In this study the low BMD detected in our patients was both at baseline and follow-up independent of diet restriction. A yearly DEXA would be highly beneficial for early detection and treatment, thus preventing osteoporosis and decreasing the risk of fractures. We also suggest the importance of searching for new emerging therapies such as enzyme substitution or gene therapy as low protein diet compliance was not enough to maintain normal bone mineral density.

Preparation and evaluation of a novel therapeutic dairy-based drink for phenylketonuria.

BACKGROUND: People with phenylketonuria need to eat a special diet which contains a low level of phenylalanine. Most of these special diets have high protein levels which contain phenylalanine. Control of phenylalanine levels in the early years of life is crucial and remains important throughout childhood, especially for cognitive function and behavior. AIMS: The current study evaluated the biological and sensory properties of a novel dairy-based drink for patients with phenylketonuria (PKU). METHODS AND MATERIALS: The novel dairy-based drink was prepared by emulsifying corn germ oil with casein glycomacropeptide (GMP) solution in milk permeates. The chemical composition and sensory properties of the dairy-based drink were determined. In addition, the dairy-based drink was nutritionally evaluated using patient volunteers. These patients followed a strict diet limiting phenylalanine in their food. Phenylalanine levels were measured before and after three days of consuming the dairy-based drink. RESULTS: The results of the sensory evaluation showed that the product was ranked that there were decreases in "good" and was acceptable by all test panels and volunteers. Serum phenylalanine levels in all volunteers decreased between 30% - 80%. CONCLUSIONS: The data obtained from the sensory evaluation and the decreases in serum phenylalanine levels encourage us to utilize this formulated dairy-based drink for therapeutic feeding of PKU patients.