Chondrodysplasia with multiple dislocations: comprehensive study of a series of 30 cases.

The group of chondrodysplasia with multiple dislocations includes several entities, characterized by short stature, dislocation of large joints, hand and/or vertebral anomalies. Other features, such as epiphyseal or metaphyseal changes, cleft palate, intellectual disability are also often part of the phenotype. In addition, several conditions with overlapping features are related to this group and broaden the spectrum. The majority of these disorders have been linked to pathogenic variants in genes encoding proteins implicated in the synthesis or sulfation of proteoglycans (PG). In a series of 30 patients with multiple dislocations, we have performed exome sequencing and subsequent targeted analysis of 15 genes, implicated in chondrodysplasia with multiple dislocations, and related conditions. We have identified causative pathogenic variants in 60% of patients (18/30); when a clinical diagnosis was suspected, this was molecularly confirmed in 53% of cases. Forty percent of patients remain without molecular etiology. Pathogenic variants in genes implicated in PG synthesis are of major importance in chondrodysplasia with multiple dislocations and related conditions. The combination of hand features, growth failure severity, radiological aspects of long bones and of vertebrae allowed discrimination among the different conditions. We propose key diagnostic clues to the clinician.

MUCOLIPIDOSIS II INFANTS PRESENTING WITH SKELETAL DEFORMITIES MIMICKING RICKETS AND A NEW MUTATION IN GNPTAB GENE.

Mucolipidosis II or I-cell disease is a rare lysosomal enzyme hydrolase trafficking due to deficient activity of the multimeric enzyme UDP-Nacetylglucosamine-l-phosphotransferase. It is a severe inborn error of lysosomal storage that causes progressive multisystem deterioration and death within the first year of life. The diagnosis of ML II is often difficult in an infant due to clinical variety, phenotypic overlap and the enzyme analysis required. Mucolipidosis II and rickets may have similar physical, biochemical and radiographic findings in newborns. The diagnosis of Mucolipidosis II is often missed, as it may present with rickets-like picture. In this article, we describe two neonatal mucolipidosis II patients mimicking rickets, and we evaluated them by clinical, metabolic and imaging findings via literature and also emphasized the difficulties in diagnosis of this rare disease.

The clinical spectrum of a rare chromosomal abnormality: Isochromosome 18p.

Isochromosome 18p is a rare chromosomal disorder that occurs with a frequency of approximately one in every 180,000 live births, and affects both genders equally. MOst cases result from a de novo formation. In the literature, there are currently only a small number of reports that describe the phenotypic and clinical features of Isochromosome 18p. In this article, we report six cases that displayed the phenotypic and clinical features of Isochromosome 18p, and which were subsequently confirmed by conventional karyotyping and fluorescence in situ hybridization. We also discuss the clinical features of these patients in the context of the cases previously reported in the literature.

22q11.2 syndrome due to maternal translocation t(18;22) (pl1.2;q11.2).

22q11.2 deletion syndrome is a pattern of malformations resulting from abnormalities during cephalic neural crest migration and during the development of the third and fourth branchial arch. It is also known as DiGeorge syndrome, as it is most often associated with a de novo 3 Mb hemizygous 22q11.2 deletion. The recognition of similarities and phenotypic overlap between DiGeorge syndrome and other disorders associated with genetic defects in 22q11 has led to an expanded description of the phenotypic features of this syndrome. Indeed, the extent of this phenotypic variability can often make it difficult to accurately diagnose DiGeorge syndrome. Tertiary monosomy resulting from the 3:1 segregation of the respective chromosomal segments of the chromosomes involved in a balanced translocation in meiosis is rarely reported in the literature. In this report, we present a female infant with dysmorphic facial features, microcephaly, a cleft palate, unilateral membranous choanal atresia, convulsions, hypocalcemia, semilobar holoporencephaly and echocardiographic abnormalities. To the best of our knowledge, this is the first description of a newborn displaying both DiGeorge syndrome and deletion 18p syndromes.

Single nucleotide polymorphism and production of IL-1ß and IL-10 cytokines in febrile seizures.

Inflammation and genetics may play a role in the pathogenesis of febrile seizures. The aim of this study was to investigate the spontaneous and lipopolysaccharide (LPS)-induced production of IL-1ß and IL-10, and the association between IL-1ß (-511) and IL-10 (-1082) single nucleotide polymorphisms with LPS-induced cytokine production. The study included 92 febrile seizure patients and 132 healthy controls. First, we isolated genomic DNA and by using PCR-RFLP we genotyped the individuals for the cytokines gene polymorphism. Second, peripheral mononuclear cells of the individuals were isolated and stimulated with LPS to measure secretion capacity of IL-1ß and IL-10 using specific ELISA kits. We found that both the IL-1ß and IL-10 production was increased in febrile seizures. The rapid increase of IL-1ß production in the supernatants of the LPS-induced cells was significantly higher at the fourth and the twenty-fourth hours in febrile and complex febrile seizures, respectively. The distribution of IL-10 (-1082) G allele differs significantly between cases and controls. The IL-1ß (-511) G/A and the IL-10 (-1082) G/A genotype combination was found to be higher in patients with febrile seizure. Our results showed that IL-1ß and IL-10 production was not influenced by the single nucleotide polymorphisms in the pathogenesis of febrile seizures.