CO-OCCURRENCE OF PRIMARY MICROCEPHALY CAUSED BY A NOVEL HOMOZYGOUS ASPM MUTATION ALONG WITH X-LINKED ICHTHYOSIS IN THE SAME PATIENT

Autosomal recessive primary microcephaly is a heterogeneous genetic disorder caused by genes that affect neurogenesis. This form of microcephaly has not been associated with other congenital anomalies. ASPM mutations have been identified as the major cause implicated in autosomal recessive primary microcephaly. X-linked recessive ichthyosis, is an inborn error of steroid sulfatase metabolism characterized by dark and adhesive scaly skin. Here, we examined an Egyptian boy presenting with microcephaly and simplified gyral pattern. Additionally, he had ichthyosis that goes with the X-linked type. Mutation analyses of the ASPM gene for autosomal recessive primary microcephaly and STS gene of X-linked recessive ichthyosis were conducted revealing a co-occurrence of a novel homozygous splice site mutation of ASPM gene (c.2936+1G>A) and a partial deletion of STS spanning from exon 7-10. We propose that the phenotype of our patient results from the combined effects of mutations in both ASPM and STS that account for the neurological signs and skin manifestations, respectively. The association of isolated X-linked recessive ichthyosis and autosomal recessive primary microcephaly has never been reported in the literature. Careful clinical and genetic assessment of patients with atypical clinical phenotypes is crucial for detecting such rare double mutations and thus proper genetic counseling.

A FEMALE PATIENT WITH DUPLICATION OF 7p13-pter ASSOCIATED WITH DEL 20p13pter RESULTING FROM MALSEGREGATED PATERNAL 7;20 BALANCED TRANSLOCATION

Duplication of the short arm of chromosome 7 is a genomic disorder presenting with distinctive facies including hypertelorism, large anterior fontanel, and intellectual disability. A 2½-year-old Egyptian girl was referred because of cleft palate and dysmorphic features. She showed clinical manifestations of duplication of 7p, along with atypical features of corpus callosum hypogenesis and skeletal anomalies. Chromosome analyses revealed unbalanced translocations involving the short arms of chromosomes 7 and 20 due to malsegregation of a paternal balanced translocation 7;20. Fluorescence in situ hybridization analysis (FISH) of the female patient showed partial trisomy 7p and a subtelomeric monosomy 20p. Thus, the karyotype of our patient is 46,XX,der(20) (7pter --> 7p13::20p13 --> 20qter). In this report, we present the clinical phenotype of this patient with duplication of 7p and review the literature.

Chilblains as a diagnostic sign of aicardi-goutières syndrome

Aicardi-Goutières syndrome (AGS) is a genetically heterogeneous disorder showing variability in age of onset and clinical features. Chilblain lesions have been described in AGS patients and recent papers have discussed the clinical, molecular and cutaneous histopathological overlap with chilblain lupus. Here we report on 2 unrelated children with AGS and chilblain lesions, whose clinical histories and examination findings well illustrate the wide phenotypic variability that can be seen in this pleiotropic disorder. Although both patients show remarkable similarity in the histopathology of their associated skin lesions, with thrombi formation, fat necrosis and hyalinization of the subcutaneous tissue, we note that the histopathology reported in other AGS cases with chilblains does not necessarily demonstrate this same uniformity. Our findings highlight the significant role of the characteristic chilblain skin lesions in the diagnosis of AGS, and variability in the associated histopathology which may relate to the stage and severity of the disease.

Expanding CEP290 mutational spectrum in ciliopathies

Ciliopathies are an expanding group of rare conditions characterized by multiorgan involvement, that are caused by mutations in genes encoding for proteins of the primary cilium or its apparatus. Among these genes, CEP290 bears an intriguing allelic spectrum, being commonly mutated in Joubert syndrome and related disorders (JSRD), Meckel syndrome (MKS), Senior-Loken syndrome and isolated Leber congenital amaurosis (LCA). Although these conditions are recessively inherited, in a subset of patients only one CEP290 mutation could be detected. To assess whether genomic rearrangements involving the CEP290 gene could represent a possible mutational mechanism in these cases, exon dosage analysis on genomic DNA was performed in two groups of CEP290 heterozygous patients, including five JSRD/MKS cases and four LCA, respectively. In one JSRD patient, we identified a large heterozygous deletion encompassing CEP290 C-terminus that resulted in marked reduction of mRNA expression. No copy number alterations were identified in the remaining probands. The present work expands the CEP290 genotypic spectrum to include multiexon deletions. Although this mechanism does not appear to be frequent, screening for genomic rearrangements should be considered in patients in whom a single CEP290 mutated allele was identified.

Anorectal anomalies, diaphragmatic defect, cleft palate, lower lip pits, hypopigmentation and hypogammaglobulinemia A in Kabuki syndrome: a rare combination

We report a rare combination of anomalies in an Egyptian girl with Kabuki syndrome (KS). The 26-month-old girl had imperforate anus with rectovestibular fistula, diaphragmatic defect, congenital heart defects, cleft palate, lower lip pits, hypopigmentation, seizures, hypogammaglobulinemia A, hyperlaxity of joints and premature breast development. This unique combination of anomalies, proposes to carefully investigate cases with KS patient in an attempt to determine their real frequency and in order to improve clinical management. Further, it raises a question about factors determining the variability in phenotypic expression among cases with KS. To our knowledge, this is the first case of KS to be reported from Egypt.

Phenotypic variability in Micro syndrome: report of new cases

The authors describe seven Egyptian patients (5 males and two females) with microcephaly, mild microphthalmia, microcornea, congenital cataracts and hypogenitalism (only in males). These features (after excluding possible non-genetic causes) are consistent with the diagnosis of Micro syndrome. Clinical, neurological, ophthalmologic examinations and brain imaging and electrophysiological studies were performed in all patients. Three cases had characteristic facial features consistent with those originally described in the Micro syndrome whilst the rest of the cases had clearly different facies to that of the original patients of Micro syndrome but similar to those described in Martsolf syndrome. The patients had a variable degree of brain atrophy but hypogenesis of the corpus callosum was evident only in five patients. Abnormal gyral pattern, small cerebellum, vermian hypoplasia and delayed myelination were additional imaging findings in 3 cases. All patients had delayed visual evoked potential but normal electroretinogram. The frequently-reported parental consanguinity emphasizes the major role of the single gene inheritance. Mutation analysis for two patients showed homozygous nonsense mutation of RAB3GAP1 in one while the other showed no evidence of linkage to either RAB3GAP1 or RAB2GAP2. Based on these cases and review of the literature, RAB3GAP genes dysregulation may result in a spectrum of phenotypes that range from Micro syndrome to Martsolf syndrome.

Aicardi-Goutières syndrome: clinical and neuroradiological findings of 10 new cases

AIM

To describe the clinical and neuroimaging findings in new cases with Aicardi-Goutières syndrome (AGS) from Egypt.

METHODS

Ten patients with progressive encephalopathy, bilateral calcification of the basal ganglia and spastic quadriplegia were described. Feeding difficulties, irritability, unexplained episodic fever and acrocyanosis were also observed. They were diagnosed as AGS after excluding possible non-genetic causes (especially TORCH) and because of the high interferon-alpha (IFN-alpha) level in cerebrospinal fluid (CSF) in two children who underwent this specific investigation.

RESULTS

Six patients had postnatal microcephaly. Putamen was by far the most common site of calcification (nine cases) inside the basal ganglia. Calcifications were extended to the white matter, periventricular and cerebellum in three cases. Brain atrophy and/or white matter demyelination were evident in most of the cases. Further, hypogenesis of corpus callosum was detected in two cases; one of them had in addition cerebellar hypoplasia, atrial septal defect (ASD) and horseshoe kidney. To the best of our knowledge, the association of these congenital abnormalities has not been reported before in AGS. Eight families were consanguineous.

CONCLUSION

This paper presents variability in both age of onset, clinical picture and neuroimaging findings even in the same family, comprising new congenital abnormalities associated with AGS and subsequently expanding the spectrum of heterogeneity. The observation of familial cases and both affected males and females emphasized the major role of the single gene inheritance.

Growth charts of Egyptian children with Down syndrome (0-36 months)

A study established growth and growth velocity curves for weight, length and head circumference in 350 Egyptian Down syndrome children (188 males and 162 females) from 0-36 months. Down syndrome children had poorer growth variables than normal healthy children through the first 3 years of life. Down syndrome children with associated congenital heart disease (90 cases) had significantly lower weight, especially in girls, compared with those without heart disease. In the first 2 years, growth velocity for weight and head circumference were higher in Down syndrome females than males, while growth velocity for length was higher in males. Down syndrome boys had slightly higher velocity of length than normal children in the first 3 years of life.