Genetic study of eight Egyptian patients with pycnodysostosis: identification of novel CTSK mutations and founder effect.

This is the first Egyptian study with detailed clinical and orodental evaluation of eight patients with pycnodysostosis and identification of four mutations in CTSK gene with two novel ones and a founder effect. INTRODUCTION: Pycnodysostosis is a rare autosomal recessive skeletal dysplasia due to mutations in the CTSK gene encoding for cathepsin K, a lysosomal cysteine protease. METHODS: We report on the clinical, orodental, radiological, and molecular findings of eight patients, from seven unrelated Egyptian families with pycnodysostosis. RESULTS: All patients were offspring of consanguineous parents and presented with the typical clinical picture of the disorder including short stature, delayed closure of fontanels, hypoplastic premaxilla, obtuse mandibular angle, and drum stick terminal phalanges with dysplastic nails. Their radiological findings showed increased bone density, acro-osteolysis, and open cranial sutures. Mutational analysis of CTSK gene revealed four distinct homozygous missense mutations including two novel ones, c.164A>C (p. K55T) and c.433G>A (p.V145M). The c.164A>C (p. K55T) mutation was recurrent in three unrelated patients who also shared similar haplotype, suggesting a founder effect. CONCLUSION: Our findings expand the mutational spectrum of CTSK gene and emphasize the importance of full clinical examination of all body systems including thorough orodental evaluation in patients with pycnodysostosis.

Batch bioethanol production via the biological and chemical saccharification of some Egyptian marine macroalgae.

AIMS: Marine seaweeds (macroalgae) cause an eutrophication problem and affects the touristic activities. The success of the production of the third-generation bioethanol from marine macroalgae depends mainly on the development of an ecofriendly and eco-feasible pretreatment (i.e. hydrolysis) technique, a highly effective saccharification step and finally an efficient bioethanol fermentation step. Therefore, this study aimed to investigate the potentiality of different marine macroalgal strains, collected from Egyptian coasts, for bioethanol production via different saccharification processes. METHODS AND RESULTS: Different marine macroalgal strains, red Jania rubens, green Ulva lactuca and brown Sargassum latifolium, have been collected from Egyptian Mediterranean and Red Sea shores. Different hydrolysis processes were evaluated to maximize the extraction of fermentable sugars; thermochemical hydrolysis with diluted acids (HCl and H2 SO4 ) and base (NaOH), hydrothermal hydrolysis followed by saccharification with different fungal strains and finally, thermochemical hydrolysis with diluted HCl, followed by fungal saccharification. The hydrothermal hydrolysis of S. latifolium followed by biological saccharification using Trichoderma asperellum RM1 produced maximum total sugars of 510 mg g-1 macroalgal biomass. The integration of the hydrothermal and fungal hydrolyses of the macroalgal biomass with a separate batch fermentation of the produced sugars using two Saccharomyces cerevisiae strains, produced approximately 0·29 g bioethanol g-1 total reducing sugars. A simulated regression modelling for the batch bioethanol fermentation was also performed. CONCLUSIONS: This study supported the possibility of using seaweeds as a renewable source of bioethanol throughout a suggested integration of macroalgal biomass hydrothermal and fungal hydrolyses with a separate batch bioethanol fermentation process of the produced sugars. SIGNIFICANCE AND IMPACT OF THE STUDY: The usage of marine macroalgae (i.e. seaweeds) as feedstock for bioethanol; an alternative and/or complimentary to petro-fuel, would act as triple fact solution; bioremediation process for ecosystem, renewable energy source and economy savings.

Zoledronic acid in children with osteogenesis imperfecta and Bruck syndrome: a 2-year prospective observational study.

UNLABELLED: Treatment with zoledronic acid (ZA) over 2 years, among 33 children with osteogenesis imperfecta (OI) and five Bruck syndrome cases, showed reduction in fracture rates, pain, and improvement in bone mineral density (BMD) and motor milestones of development. This is the first study reporting the use of bisphosphonates in patients with Bruck syndrome (BS). INTRODUCTION: OI and BS are genetic disorders that result in bone fragility and reduced BMD. There is little literature describing the efficacy and safety of ZA in this population. In this study, we assess the response to treatment with ZA at six monthly intervals in Egyptian children with OI and BS for a period of 2 years. METHODS: Thirty-three patients with OI and five patients with BS were treated with 0.1 mg/kg ZA intravenously every 6 months for 2 years during which they were followed up using different parameters. A clinical severity score (CSS) was applied to the patients before and 2 years after the start of therapy. Comparison of disease severity and response to ZA treatment between autosomal-dominant (AD) and autosomal-recessive (AR) OI patients was also done. RESULTS: After 6 months of treatment, OI and BS patients showed a significant increase in BMD Z-scores (P < 0.003 in the spine and P < 0.004 in the hip), together with a significant drop in fracture rate (P < 0.001), relief of pain (P < 0.001), and improvement in ambulation (P < 0.001). CSS was significantly reduced after 2 years of treatment in both OI and BS patients. AR-OI patients were more severely affected than AD-OI patients and showed more significant improvement. CONCLUSION: Zoledronic acid proved to be safe and effective in the treatment of OI and BS. The biannual infusion protocol was convenient to patients. There was a positive correlation between disease severity and benefits of the treatment. The use of the CSS proved to be of value in the assessment of the degree of severity in OI, and with some modifications, it was a valuable tool for the assessment of response to treatment.

ROBERTS SYNDROME: CLINICAL AND CYTOGENETIC STUDIES IN 8 EGYPTIAN PATIENTS AND MOLECULAR STUDIES IN 4 PATIENTS WITH GENOTYPE/PHENOTYPE CORRELATION.

The Roberts syndrome (RBS) is a rare autosomal recessive disorder caused by mutation in ESCO2 gene. Among over 150 reported international cases, 16 cases are Egyptian including the presently reported patients. The current study reports 8 new Egyptian patients from 7 unrelated consanguineous families investigating clinical phenotype as well as cytogenetic changes in all cases and mutational spectrum in 4 cases. Clinical, orodental, cytogenetic and molecular studies were done to investigate genotype/phenotype correlation. Evaluation of the studied 8 patients showed that they all exhibited the main limb and craniofacial features of Roberts syndrome. Cytogenetic studies including centromeric separation and puffing by Giemsa and DAPI stains and for the first time in Egypt analysis for premature centromeric division by FISH showed consistent centromeric separation in all studied cases. Molecular studies of 4 available patients showed that they all have ESCO2 gene mutation. We conclude that RBS has a well-defined clinical spectrum. The cytogenetic changes are due to sister chromatid cohesion defects which lead to mitotic dysfunction. We confirmed previous results of lack of genotype/phenotype correlation. We also confirmed that the severity of limb malformation correlates with craniofacial manifestations. We recommend detailed evaluation of orodental changes for further definition of the phenotype and for proper patient management. We emphasize the need for further studies for the frequency of premature centromeric separation by FISH as a possible indicator of phenotypic severity.

Loss-of-function mutations in the cathepsin C gene result in periodontal disease and palmoplantar keratosis.

Papillon-Lefèvre syndrome, or keratosis palmoplantaris with periodontopathia (PLS, MIM 245000), is an autosomal recessive disorder that is mainly ascertained by dentists because of the severe periodontitis that afflicts patients. Both the deciduous and permanent dentitions are affected, resulting in premature tooth loss. Palmoplantar keratosis, varying from mild psoriasiform scaly skin to overt hyperkeratosis, typically develops within the first three years of life. Keratosis also affects other sites such as elbows and knees. Most PLS patients display both periodontitis and hyperkeratosis. Some patients have only palmoplantar keratosis or periodontitis, and in rare individuals the periodontitis is mild and of late onset. The PLS locus has been mapped to chromosome 11q14-q21 (refs 7, 8, 9). Using homozygosity mapping in eight small consanguineous families, we have narrowed the candidate region to a 1.2-cM interval between D11S4082 and D11S931. The gene (CTSC) encoding the lysosomal protease cathepsin C (or dipeptidyl aminopeptidase I) lies within this interval. We defined the genomic structure of CTSC and found mutations in all eight families. In two of these families we used a functional assay to demonstrate an almost total loss of cathepsin C activity in PLS patients and reduced activity in obligate carriers.

Clinical and cytogenetic study of a case with familial chromosomal translocation presenting with facial dysmorphism and axial neuropathy.

We report on a 9-year-old female patient presenting with muscle weakness, facial dysmorphism and mild mental retardation. She had low birth weight, developmental delay, hypotonia and hyporeflexia and difficulties in climbing the stairs. EMG revealed axonal polyneuropathy affecting both upper and lower limbs. She was the child of non-consanguineous parents, her cytogenetic findings revealed 46,XX,t(12;14)(q14;q23). The mother's karyotype was normal 46,XX while the father's karyotype was 46,XY,t(12;14)(q14;q23) the same as his daughter. Her normal sister's karyotype was also 46,XX,t(12; 14) (q14;q23). Fluorescence in situ hybridization (FISH) was used to elucidate the breakpoints and Array-CGH was done for the patient to confirm the balanced translocation. This observation is of interest because it represents a rare case of a balanced translocation with abnormal phenotype. Mutant genes causing axonal neuropathy have been located on various chromosomes other than 12q14 or 14q24. This report shows the importance of molecular cytogenetics and its correlation with abnormal phenotype and the possibility of another gene locus at the presently studied chromosomal breakpoints. Detailed correlations between chromosome aberrations and their phenotypes are of invaluable help in localising genes for axonal polyneuropathy.

A report of three patients with MMP2 associated hereditary osteolysis.

Osteolysis syndromes are rare hereditary disorders characterized by destruction and resorption of affected bones. The current study adds three new patients from two unrelated consanguineous families with a severe form of inherited osteolysis. Clinical examination, radiological, biochemical, ultrastructural and molecular studies were conducted. Clinical and radiological studies suggested the diagnosis of Torg-Winchester syndrome. The three affected patients were homozygous for novel MMP2 gene mutations which confirmed the diagnosis. Our patients are the first to be reported from Egypt thus, supporting the pan ethnic nature of the disease.

The most encountered groups of genetic disorders in Giza Governorate, Egypt.

This study presents the prevalence, relative frequency, and analysis of genetic diseases/malformations in 73260 individuals. Cases included were ascertained from: Pediatric outpatient clinics of two governmental hospitals and two primary health care centers (PHCCs) in Giza Governorate; Neonatal intensive care unit (NICU) in the selected hospitals and Outpatients Human Genetics Clinics (NRC). 62819 persons visited the outpatients clinics of selected hospitals and PHCCs in Giza governorate. Out of these persons 731 cases (1.16%) proved to have known genetic disorders or malformations. 7755 neonates were delivered in the selected hospitals. Out of these neonates 666 newborns entered NICU and 3% (20 neonates) of them had genetic or congenital disorders. Also, 2686 patients were ascertained from the Human Genetics Clinics, NRC. The overall parental consanguinity rate among the 3417 diagnosed cases was 55%, ranging from 29.5-75%. The study showed a high prevalence of genetic/malformation disorders among Egyptians, with frequencies comparable to other Arab populations (Tab. 4, Ref. 25). Full Text (Free, PDF) www.bmj.sk.

Phenotypic and cytogenetic spectrum of 9p trisomy.

Trisomy 9p is one of the most frequent autosomal anomalies compatible with long survival rate. The spectrum of clinical severity in trisomy 9 roughly correlates with the extent of trisomic chromosome material. Trisomy 9p is a clinically well delineated syndrome and of all stigmata craniofacial dysmorphism is most specific. In this study we report five cases with de novo trisomy 9p. The study aimed at the identification of the genotype/phenotype correlations in patients with different breakpoints. GTG banding, DAPI stain, whole chromosome paint, centromere, telomere and 9p21 specific locus probes demonstrated that partial trisomy 9p in case 1 was due to isochromosome 9p with translocation of the long arm of re-arranged chromosome 9 onto the short arm of chromosome 13, cases 2 and 3 had intrachromosomal duplication of the short arm of chromosome 9 [dup(9)(p21p24)], case 4 had "classical" 9p trisomy and case 5 had duplication of whole short arm and part of the long arm of chromosome 9 (partial 9 trisomy). Although cases 1 to 4 had trisomy involving 9p, cases 1 and 2 exhibited the classical clinical manifestations of 9p trisomy, while cases 3 and 4 had additional features overlapping with Coffin-Siris syndrome. The present study strengthens the association of Coffin-Siris syndrome and 9p, the significance of such observations may point to possible gene location of Coffin-Siris syndrome on 9p. Case 5 had additional manifestations more than those typical of trisomy 9p which could be due to duplication of 9q21 region. Wide gap between 1st and 2nd toes, observed in the studied cases, can be added to the phenotype of this trisomy. Three of our cases had brain malformations, case 3 had dilated ventricles with hypogenesis of corpus callosum, case 4 had agenesis of corpus callosum, and case 5 had Dandy-Walker malformation. We also suggest that dosage effects of genes located in 9pter-q22 contribute to the etiology of Dandy-Walker syndrome. We recommend MRI studies as a routine in all cases with trisomy 9p.

Roberts syndrome: study of 4 new Rgyptian cases with comparison of clinical and cytogenetic findings.

Roberts syndrome is a rare autosomal recessive genetic disorder (MIM 268300). It is characterized by pre and postnatal growth retardation, severe shortening of limbs with radial defects, oligodactyly and characteristic facial features. The present study reports 4 new cases of Roberts syndrome from 3 families presenting variable phenotypes. Patients were thoroughly investigated clinically and cytogenetically. By reviewing literature, we compared our cases to those previously reported. The rating severity system proposed by Van den Berg and Francke (30) was applied to correlate the phenotypic and cytogenetics changes. We observed more severe reduction defects in the upper limbs than in the lower limbs. While the main reduction defects in the upper limbs involved the thumb and radius ranging to phocomelia, absent or severely hypoplastic fibula was the main lower limb involvement. We emphasize this finding in the present investigation. Heterochromatin repulsion of chromosomes derived from Roberts syndrome patients is a characteristic cytogenetic abnormality. It was a constant finding in our studied patients demonstrated by DABI stain which supports the possibility that mutations in Roberts syndrome lie in centromere related proteins which may also play a role in body patterning. This was proved recently by Vega et al. (31). Application of the clinical rating score and its correlation with cytogenetic changes showed negative results. Cytogenetic studies in normal obligatory heterozygotes parents showed no changes. Phenotypic variability within the same family as well as between different families was observed. The ascertainment of 4 cases with Roberts syndrome from 3 Egyptian consanguineous families during one year in our department may indicate a high frequency of the Roberts syndrome allele among Egyptians. This confirms the need for molecular studies for early and accurate prenatal diagnosis to prevent such dramatic malformation syndrome.

Unusual pattern of inheritance and orodental changes in the Ellis-van Creveld syndrome.

Ellis-van Creveld (EVC) syndrome (chondroectodermal dysplasia, mesoectodermal dysplasia, OMIM 225500) is an autosomal recessive skeletal dysplasia characterized by short limbs, short ribs, postaxial polydactyly and dysplastic nails and teeth. Oral manifestations tend to be pathognomonic such as multiple broad labial frenula and congenital missing teeth. In this study we report three Egyptian families with six cases of EVC syndrome. An unusual pattern of inheritance with father to son or to daughter transmission was observed in 2 consanguineous families thus demonstrating pseudo-dominant inheritance, probably for the first time in the literature. A new consistent orodental anomaly found in all our cases was bifid tip of the tongue. We emphasize study of orodental anomalies in future cases for accurate diagnosis of Ellis-van Creveld syndrome and its probable differential diagnosis from Weyers acrodental dysostosis.

Haplotypes and mutations of the PAH locus in Egyptian families with PKU.

A high degree of molecular heterogeneneity at the phenylalanine hydroxylase (PAH) locus was established by examining RFLP haplotypes and PAH mutations in the families of 13 Egyptians with phenylketenouria (PKU). Thirteen different haplotypes were unequivocally determined in these kindreds. Haplotypes 1.8, 3.9, 4.3, 7.8, 22.11, 27.6, and 52.8 were found segregating with normal chromosomes, whilst haplotypes 1.8, 5.9, 23.8, 32.8, the newly assigned 73.9, and two as yet incomplete but novel haplotypes were found segregating with the mutant chromosomes. There was no particular preference for a single haplotype among normal or mutant chromosomes. Nine different mutations were also identified among the 26 alleles. IVS 10nt11g (8/26), IVS 2nt5g-c (4/26), R261Q (3/26), R176X (2/26), Y206D (2/26), S231P (2/26), Y198fs [593-614del22bp]; (2/26), G46fs [136/137delG]; (1/26), and E178G (1/26). Six of these mutations (IVS 2nt5g-c, R176X, Y198fs, R261Q, S231P, and IVS 10nt11g) are common to other Mediterranean populations. Two mutations not previously reported in the Mediterranean basin were also observed (Y206D and G46fs). These intriguing preliminary findings confirm IVS 10nt11g as a major mutation among Mediterranean mutations and demonstrate the need for a more comprehensive study of Arab populations to confirm the uniqueness of the two novel mutations to the Egyptian population.

Neu Laxova syndrome in two Egyptian families.

We report on 2 Egyptian girls from 2 families with 8 affected relatives, 4 in each family. The 2 propositae had unusual facial appearance, severe microcephaly, generalized edema, contractures of limbs, and generalized ichthyotic skin lesions. Findings in the present 2 patients were compared with those in previously reported cases of Neu Laxova syndrome. In our cases, consanguinity, affected sibs, and affected cousins were noted. Autosomal recessive inheritance and lethality are emphasized. A high frequency of the Neu Laxova syndrome in Egyptians is suspected as a result of the increased consanguinity rate.

Hypogenitalism in the acrocallosal syndrome.

We have studied a boy with acrocallosal syndrome and hypogenitalism. He was the offspring of double first cousins. He had unusual facial appearance, postaxial polydactyly with unilateral soft tissue syndactyly of fingers, mental retardation, and absence of corpus callosum. Findings in the present case were compared with those of previously reported cases. Other syndromes associated with agenesis of the corpus callosum must be differentiated. The main differences between the acrocallosal syndrome and the Greig syndrome are outlined with particular emphasis on digital anomalies. The acrocallosal syndrome is an autosomal recessive trait with variable expressivity. Hypogenitalism may be a presenting feature. Positive consanguinity provides further evidence for autosomal recessive inheritance.

Cataract, hypertrichosis, and mental retardation (CAHMR): a new autosomal recessive syndrome.

We have studied 2 Egyptian sibs (the offspring of normal first cousins) with congenital cataract, hypertrichosis, mental retardation, and normal chromosomes. Review showed that the condition of our patients was not similar to any previously reported entity. POSSUM lists 84 syndromes with any of the above 3 main traits. Two disorders with cataract and mental retardation, Martsolf syndrome and Mollica-Pavone-Anterer syndrome, have overlapping manifestations and therefore are particularly differentiated from our cases. We suggest that the association of congenital cataract, hypertrichosis, and mental retardation observed in this report represents a new autosomal recessive syndrome.

Greig cephalopolysyndactyly syndrome with dysgenesis of the corpus callosum in a Bedouin family.

We report on the first known Bedouin family with Greig cephalopolysyndactyly syndrome (MIM 175700). The index patient and his father shared pre- and postaxial polysyndactyly, mild mental retardation, and corpus callosum dysgenesis. Their phenotypic findings were compared with reported cases of both Greig cephalopolysyndactyly (GCPS) and acrocallosal syndromes. This family represents the second report of the rare occurrence of dysgenesis of the corpus callosum in GCPS.

Molecular analysis of androgen resistance syndromes in Egyptian patients.

Androgen resistance syndromes [i.e. 5 alpha-reductase deficiency (5 alpha RD) and androgen receptor (AR) defects] are frequently reported among Egyptian intersex patients. This study examined AR and 5 alpha-reductase 2 (5 alpha R2) gene mutations among a sample of such cases as a first step towards instituting a screening program. Five families with a typical hormonal profile of 5 alpha RD were screened for major deletions of exons 3-5 of the 5 alpha R2 gene, using polymerase chain reaction (PCR) and electrophoresis. Thereafter, screening for point mutations was carried out by single strand conformational polymorphism (SSCP) analysis, followed by nucleotide sequencing. Seven patients with androgen insensitivity syndrome (AIS) were subjected to molecular analysis of AR exons B-H by a similar protocol, except for the use of denaturing gradient gel electrophoresis (DGGE) for screening point mutations. No major deletions were found in either gene. One family had abnormal electrophoretic mobility on SSCP of exon 5 of the 5 alpha R2 gene, resulting from a point mutation (C to T substitution) at codon 246. Another family, showing retarded mobility on DGGE, had a point mutation (G to A substitution) at codon 889 of the AR gene. In conclusion, the study revealed two mutations previously reported in other geographically distinct populations, inferring the possibility of mutational hot spots in the genes.

Lenz microphthalmia syndrome: three additional cases with rare associated anomalies.

Lenz microphthalmia syndrome is an extremely rare inherited disorder, characterized by unilateral or bilateral microphthalmia. In rare cases affected patients exhibit complete absence of eye or blepharoptosis resulting in visual impairment. Additional physical abnormalities are often associated with this disorder, orofacial, digital, skeletal and urogenital abnormalities. Here we present three cases of Lenz microphthalmia with additional manifestations: two brothers of first cousin mating, the elder one has bilateral congenital cataract which is a rare ophthalmological finding in this syndrome and a third case who presented to us because of ambiguous genitalia. She was 12 years old, and reared as a female. Chromosomal analysis showed 46,XY karyotype, and hormonal studies indicated 5-alpha reductase deficiency. This is the first report of the association of 5-alpha reductase deficiency with Lenz microphthalmia syndrome.

Expanding the phenotypic spectrum of the Baller-Gerold syndrome.

We report on two sisters off-spring of healthy consanguineous parents, where their major clinical features absent thumb, radial aplasia and craniosynostosis led to a diagnosis of Baller-Gerold syndrome BGS (OMIM:218600). Syndromes with associated preaxial reduction defects mainly Fanconi pancytopenia, VATER association, Rothmund-Thompson and Roberts phocomelia syndrome were excluded by proper clinical and cytogenetic studies. In addition to craniosynostosis and radial deficiency, our studied cases had absent or hypoplastic thumbs, postaxial polydactyly in the left foot, genital anomalies and orodental manifestations. Review of the literature depicted phenotypic variability of BGS. The presence of affected sibs the offspring of consanguineous parents confirms autosomal recessive inheritance. The observation of associated postaxial polydactyly, blue sclera, rotatory nystagmus, other skeletal and orodental anomalies broadened the spectrum of phenotypic variability. Awareness of the expanded phenotypic spectrum will improve the diagnosis and genetic counseling of BGS.

A new multiple congenital anomaly, mental retardation syndrome with preaxial brachydactyly, hyperphalangism, deafness and orodental anomalies.

We report on a child with a 'new' syndrome characterized by multiple congenital anomalies, mental retardation, sensorineural deafness, talon cusps of upper central incisors, growth retardation, bilateral symmetrical digital anomalies mainly in the form of preaxial brachydactyly and hyperphalangism of digits I-III. Because he had a similarly affected brother and his parents were cousins we suggest autosomal recessive inheritance, X-linked recessive inheritance cannot be excluded. Differential diagnosis from other syndromes with preaxial brachydactyly and hyperphalangism is presented.