HIDEA syndrome: A new case report highlighting similarities with ROHHAD syndrome.

Context: ROHHAD syndrome presents a significant resemblance to HIDEA syndrome. The latter is caused by biallelic loss-of-function variants in the P4HTM gene and encompasses hypotonia, intellectual disabilities, eye abnormalities, hypoventilation, and dysautonomia. We report the first patient identified with HIDEA syndrome from our ROHHAD cohort. Clinical case: Our patient was a 21-month-old girl who had a history of severe respiratory infections requiring intensive care, hypotonia, abnormal eye movements, and rapid weight gain. Polysomnography identified severe central hypoventilation. During her follow-up, a significant psychomotor delay and the absence of language were gradually observed. The prolactin levels were initially increased. Hypothermia was reported at 4 years. Exome sequencing identified a new homozygous truncating P4HTM variant. Discussion: Our patient met the diagnosis criteria for ROHHAD, which included rapid weight gain, central hypoventilation appearing after 1.5 years of age, hyperprolactinemia suggesting hypothalamic dysfunction, and autonomic dysfunction manifesting as strabismus and hypothermia. However, she also presented with severe neurodevelopmental delay, which is not a classic feature of ROHHAD syndrome. HIDEA syndrome presents similarities with ROHHAD, including hypoventilation, obesity, and dysautonomia. To date, only 14% of endocrinological disturbances have been reported in HIDEA patients. Better delineation of both syndromes is required to investigate the eventual involvement of P4HTM, a regulator of calcium dynamics and gliotransmission, in ROHHAD patients. Conclusion: In the case of clinical evidence of ROHHAD in a child with abnormal neurological development or eye abnormalities, we suggest that the P4HTM gene be systematically interrogated in addition to the analysis of the PHOX2B gene. A better delineation of the natural history of HIDEA is required to allow further comparisons between features of HIDEA and ROHHAD. The clinical similarities could potentially orient some molecular hypotheses in the field of ROHHAD research.

[(S)un (M)ay (A)rise on SMA : the hope of a region without spinal muscular atrophy]. / (S)un (M)ay (A)rise on SMA : l'espoir d'une région sans amyotrophie spinale.

The treatment of spinal muscular atrophy (SMA) has considerably changed over the last 3 years. Several approaches that aim to increase the deficient SMN protein have demonstrated an efficacy that is inversely correlated with disease duration. In this context, newborn screening (NBS) is increasingly considered as the next step in several countries or regions. In 2018, we initiated a pilot study for NBS of SMA in French- and German-speaking Belgium. We aim to evaluate the feasibility, the efficacy, and the cost-effectiveness of such a program. Initially covering the region of Liege, the program was recently extended to the whole Southern Belgium and currently covers about 55.000 newborns per year. On June 1st 2019, 35.000 newborns had been screened and 5 affected babies were identified and referred to neuromuscular centers for early treatment. A full evaluation of the program will take place after three years to consider the inclusion of SMA screening in the publically-funded NBS program in Southern Belgium.

La prise en charge de l'amyotrophie spinale antérieure (SMA) a considérablement évolué au cours des trois dernières années. Les différents essais visant à augmenter la production de la protéine SMN déficitaire dans la SMA ont systématiquement montré une efficacité inversement proportionnelle à la durée de la maladie. Dès lors, l'implémentation d'un programme de dépistage néonatal s'est rapidement imposée comme une évidence médico-économique dans de nombreux pays. Dans ce contexte, nous avons initié un programme de dépistage néonatal pour la SMA en Belgique francophone et germanophone. En 2018, une étude pilote de trois ans visant à évaluer la faisabilité, l'efficacité et la rentabilité du screening a été initiée au sein du centre de dépistage de Liège. L'étude a récemment été étendue à l'ensemble de la Fédération Wallonie-Bruxelles (FWB) pour couvrir environ 55.000 naissances annuelles. Au 1er juin 2019, 35.000 bébés ont été dépistés et cinq nouveau-nés atteints de SMA ont été identifiés. Tous ont été immédiatement référés pour assurer leur prise en charge dans un centre de référence pour les maladies neuromusculaires. Une évaluation complète du programme aura lieu à l'issue de la phase pilote, afin d'envisager que la SMA soit reconnue comme maladie officielle du programme de dépistage néonatal en FWB.

GPR101 Mutations are not a Frequent Cause of Congenital Isolated Growth Hormone Deficiency.

Patients with Xq26.3 microduplication present with X-linked acrogigantism (X-LAG) syndrome, an early-childhood form of gigantism due to marked growth hormone (GH) hypersecretion from mixed GH-PRL adenomas and hyperplasia. The microduplication includes GPR101, which is upregulated in patients' tumor tissue. The GPR101 gene codes for an orphan G protein coupled receptor that is normally highly expressed in the hypothalamus. Our aim was to determine whether GPR101 loss of function mutations or deletions could be involved in patients with congenital isolated GH deficiency (GHD). Taking advantage of the cohort of patients from the GENHYPOPIT network, we studied 41 patients with unexplained isolated GHD. All patients had Sanger sequencing of the GPR101 gene and array comparative genome hybridization (aCGH) to look for deletions. Functional studies (cell culture with GH secretion measurements, cAMP response) were performed. One novel GPR101 variant, c.589 G>T (p.V197L), was seen in the heterozygous state in a patient with isolated GHD. In silico analysis suggested that this variant could be deleterious. Functional studies did not show any significant difference in comparison with wild type for GH secretion and cAMP response. No truncating, frameshift, or small insertion-deletion (indel) GPR101 mutations were seen in the 41 patients. No deletion or other copy number variation at chromosome Xq26.3 was found on aCGH. We found a novel GPR101 variant of unknown significance, in a patient with isolated GH deficiency. Our study did not identify GPR101 abnormalities as a frequent cause of GH deficiency.

Diagnostic pitfall in antenatal manifestations of CPT II deficiency.

Carnitine palmitoyltransferase II (CPT2) deficiency is a rare inborn error of mitochondrial fatty acid metabolism associated with various phenotypes. Whereas most patients present with postnatal signs of energetic failure affecting muscle and liver, a small subset of patients presents antenatal malformations including brain dysgenesis and neuronal migration defects. Here, we report recurrence of severe cerebral dysgenesis with Dandy-Walker malformation in three successive pregnancies and review previously reported antenatal cases. Interestingly, we also report that acylcarnitines profile, tested retrospectively on the amniotic fluid of last pregnancy, was not sensitive enough to allow reliable prenatal diagnosis of CPT2 deficiency. Finally, because fetuses affected by severe cerebral malformations are frequently aborted, CPT2 deficiency may be underestimated and fatty acid oxidation disorders should be considered when faced with a fetus with Dandy-Walker anomaly or another brain dysgenesis.

Clinical, cytogenetic and molecular characterization of two cases of mosaic ring chromosome 13.

The occurrence of mosaic ring chromosome 13 is rare. The mechanism of ring chromosome formation is usually associated with loss of genetic material. We report 2 cases of mosaic ring chromosome 13, resulting in deletion of 13qter. The first patient, a 15 year-old boy, presented a delayed psychomotor development, mental retardation, dysmorphic features and bleeding disorders associated with a de novo terminal 13q34 deletion. The second case was a foetus of 31 weeks with prenatal diagnosis of severe malformation such as holoprosencephaly, congenital cardiac defects, gastro-intestinal abnormalities with intrauterine growth retardation, the molecular analysis showed a de novo deletion encompassing the region 13q31.3-q34.