Incidental findings on array comparative genomic hybridization: detection of carrier females of dystrophinopathy without any family history.

Array comparative genomic hybridization (aCGH) has progressively replaced conventional karyotype in the diagnostic strategy of intellectual disability (ID) and congenital malformations. This technique increases not only the diagnostic rate but also the possibility of finding unexpected variants unrelated to the indication of referral, namely incidental findings. The incidental finding of copy number variants (CNVs) located in X-linked genes in girls addresses the crucial question of genetic counseling in the family. We report here five cases of CNVs involving the dystrophin gene detected by aCGH in girls referred for developmental delay, without any family history of dystrophinopathy. The rearrangements included three in-frame deletions; one maternally and two paternally inherited, and two frameshift duplications: one de novo and one from undetermined inheritance. In two cases, the deletion identified in a girl was transmitted by the asymptomatic father. In the case of the maternally inherited deletion, prenatal diagnosis of dystrophinopathy was proposed for an ongoing pregnancy, whereas the cause of developmental delay in the index case remained unknown. Through these cases, we discussed the challenges of genetic counseling in the family, regarding the predictive issues for male individuals at risk for a muscular dystrophy without precise knowledge of the clinical consequences of some CNVs in the DMD gene.

Systematic molecular and cytogenetic screening of 100 patients with marfanoid syndromes and intellectual disability.

The association of marfanoid habitus (MH) and intellectual disability (ID) has been reported in the literature, with overlapping presentations and genetic heterogeneity. A hundred patients (71 males and 29 females) with a MH and ID were recruited. Custom-designed 244K array-CGH (Agilent®; Agilent Technologies Inc., Santa Clara, CA) and MED12, ZDHHC9, UPF3B, FBN1, TGFBR1 and TGFBR2 sequencing analyses were performed. Eighty patients could be classified as isolated MH and ID: 12 chromosomal imbalances, 1 FBN1 mutation and 1 possibly pathogenic MED12 mutation were found (17%). Twenty patients could be classified as ID with other extra-skeletal features of the Marfan syndrome (MFS) spectrum: 4 pathogenic FBN1 mutations and 4 chromosomal imbalances were found (2 patients with both FBN1 mutation and chromosomal rearrangement) (29%). These results suggest either that there are more loci with genes yet to be discovered or that MH can also be a relatively non-specific feature of patients with ID. The search for aortic complications is mandatory even if MH is associated with ID since FBN1 mutations or rearrangements were found in some patients. The excess of males is in favour of the involvement of other X-linked genes. Although it was impossible to make a diagnosis in 80% of patients, these results will improve genetic counselling in families.

H syndrome: novel and recurrent mutations in SLC29A3.

The H syndrome (OMIM 612391) is a recently described autosomal recessive disorder characterized by cutaneous hyperpigmentation, hypertrichosis, hepatosplenomegaly, heart anomalies, hearing loss, hypogonadism, short stature (low height), hyperglycaemia/diabetes mellitus, hallux valgus, and fixed flexion contractures of the toe and finger joints.(1,2) Histologically, there is an inflammatory infiltrate consisting mainly of histiocytes, later replaced by fibrosis of the deep dermis and subcutis.(3) In total, 31 patients have been reported in the literature with the clinical phenotype characteristic of this syndrome.(1-7)

[Investigation of tall stature in children: Diagnostic work-up, review of the main causes]. / Exploration d'une avance staturale chez l'enfant : conduite à tenir pratique, principales étiologies à évoquer.

Tall stature is not a common motive for medical consultation, even though by definition 2.5 % of children in the general population are concerned. It is usually defined as height greater than+2 standard deviations (SD) using the appropriate growth chart for age and gender, or a difference greater than +2 SD between actual height and target height. With a patient presenting tall stature, the physician has to determine whether it is a benign feature or a disease. Indeed, making the diagnosis is essential for hormonal disease or genetic overgrowth syndromes. The past medical history including parents' height, prenatal and birth data, physical examination along with anthropometry (height, weight, head circumference, body mass index), and growth chart evaluation with the detailed growth pattern are generally sufficient to make the diagnosis such as familial tall stature, obesity, or early puberty. Bone age estimation may be helpful for some specific etiologies and is also necessary to help predict final adult height. After exclusion of common causes, further investigation is required. Sudden growth acceleration often reveals endocrine pathology such as early puberty, hyperthyroidism, or acrogigantism. Tall stature accompanied by dysmorphic features, congenital malformations, developmental delay, or a family medical history may be related to genetic disorders such as Marfan, Sotos, or Wiedemann-Beckwith syndromes. We relate here the most frequent etiologies of overgrowth syndromes.

Clinical presentation of PTEN mutations in childhood in the absence of family history of Cowden syndrome.

BACKGROUND: PTEN gene (MIM 601628) is a tumor suppressor gene implicated in PTEN hamartoma tumor syndromes (PHTS) including Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, and Proteus-like syndrome. Bannayan-Riley-Ruvalcaba syndrome is considered as the pediatric form of PHTS. More recently, children presenting autism spectrum disorders with macrocephaly (ASD-M) have been reported. METHODS: We report clinical data from seven patients diagnosed in childhood with a PTEN germline mutation, excluding cases of familial Cowden syndrome. RESULTS: This study underlines the variability of phenotype associated with PTEN mutations diagnosed at pediatric age. Most of the patients did not fulfill usual criteria of Bannayan-Riley-Ruvalcaba syndrome or ASD-M. CONCLUSION: PTEN testing should be considered in any child presenting with severe macrocephaly (>+4SD) and another feature of PHTS.

Transition of Mount Etna lavas from a mantle-plume to an island-arc magmatic source.

Mount Etna lies near the boundary between two regions that exhibit significantly different types of volcanism. To the north, volcanism in the Aeolian island arc is thought to be related to subduction of the Ionian lithosphere. On Sicily itself, however, no chemical or seismological evidence of subduction-related volcanism exists, and so it is thought that the volcanism-including that on Mount Etna itself-stems from the upwelling of mantle material, associated with various surface tectonic processes. But the paucity of geological evidence regarding the primary composition of magma from Mount Etna means that its source characteristics remain controversial. Here we characterize the trace-element composition of a series of lavas emitted by Mount Etna over the past 500 kyr and preserved as melt inclusions inside olivine phenocrysts. We show that the compositional change in primary magmas from Mount Etna reflects a progressive transition from a predominantly mantle-plume source to one with a greater contribution from island-arc (subduction-related) basalts. We suggest that this is associated with southward migration of the Ionian slab, which is becoming juxtaposed with a mantle plume beneath Sicily. This implies that the volcanism of Mount Etna has become more calc-alkaline, and hence more explosive, during its evolution.