12q21 Interstitial Deletions: Seven New Syndromic Cases Detected by Array-CGH and Review of the Literature.
Interstitial deletions of the long arm of chromosome 12 are rare, with a dozen patients carrying a deletion in 12q21 being reported. Recently a critical region (CR) has been delimited and could be responsible for the more commonly described clinical features, such as developmental delay/intellectual disability, congenital genitourinary and brain malformations. Other, less frequent, clinical signs do not seem to be correlated to the proposed CR. We present seven new patients harboring non-recurrent deletions ranging from 1 to 18.5 Mb differentially scattered across 12q21. Alongside more common clinical signs, some patients have rarer features such as heart defects, hearing loss, hypotonia an…
12q14.3 microdeletion involving HMGA2 gene cause a Silver-Russell syndrome-like phenotype: a case report and review of the literature
Abstract Background Silver-Russell Syndrome (SRS) is a genetic disorder characterized by intrauterine and postnatal growth restriction and normal head circumference with consequent relative macrocephaly. Addictional findings are protruding forehead in early life, body asymmetry (of upper and lower limbs) and substantial feeding difficulties. Although several genetic mechanisms that cause the syndrome are known, more than 40% of patients with a SRS-like phenotype remain without an etiological diagnosis. In the last few years, different clinical reports have suggested that mutations or deletions of the HMGA2 gene can be responsible for a SRS-like phenotype in patients with negative results of…
Expanding the phenotype of reciprocal 1q21.1 deletions and duplications: a case series
Abstract Background Recurrent reciprocal 1q21.1 deletions and duplications have been associated with variable phenotypes. Phenotypic features described in association with 1q21.1 microdeletions include developmental delay, craniofacial dysmorphism and congenital anomalies. The 1q21.1 reciprocal duplication has been associated with macrocephaly or relative macrocephaly, frontal bossing, hypertelorism, developmental delay, intellectual disability and autism spectrum disorder. Methods Our study describes seven patients, who were referred to us for developmental delay/intellectual disability, dysmorphic features and, in some cases, congenital anomalies, in whom we identified 1q21.1 CNVs by arra…
Meconial peritonitis in a rare association of partial ileal apple-peel atresia with small abdominal wall defect.
Intestinal atresia type III B (apple peel) and gastroschisis are both congenital malformations who require early surgical correction in neonatal age. Their association is very rare. We present the case of a full term infant with partial apple peel ileal atresia and a small defect of the anterior abdominal wall, complicated by in utero intestinal perforation and subsequent meconial peritonitis. We observed a partial atresia of small intestine, with involvement of terminal ileus savings of jejunum and a large part of the proximal ileum, small anterior abdominal wall defect with herniation of few bowel loops, intestinal malrotation. Paralytic ileus and infections are the main causes of morbidi…
Type IV Laryngotracheoesophageal Cleft Associated with Type III Esophageal Atresia in 1p36 Deletions Containing the RERE Gene: Is There a Causal Role for the Genetic Alteration?
The causes of embryological developmental anomalies leading to laryngotracheoesophageal clefts (LTECs) are not known, but are proposed to be multifactorial, including genetic and environmental factors. Haploinsufficiency of the RERE gene might contribute to different phenotypes seen in individuals with 1p36 deletions. We describe a neonate of an obese mother, diagnosed with type IV LTEC and type III esophageal atresia (EA), in which a 1p36 deletion including the RERE gene was detected. On the second day of life, a right thoracotomy and extrapleural esophagus atresia repair were attempted. One week later, a right cervical approach was performed to separate the cervical esophagus from the tra…
Inhaled nitric oxide as a rescue therapy in a preterm neonate with severe pulmonary hypertension: a case report
Abstract Background Inhaled nitric oxide (iNO) has been approved for the treatment of persistent pulmonary hypertension of the newborn (PPHN) in term and near-term newborns. Its role in the management of persistent pulmonary hypertension in preterm infants is not clear. Although guidelines do not exist, some studies have shown that iNO could be used as a rescue therapy in preterm neonate with severe pulmonary hypertension. Case presentation We describe the case of a preterm neonate, born at 30 + 1 weeks of gestation, with hypoxic respiratory failure not responding to maximal conventional therapy. On the third day of life echocardiography showed severe pulmonary hypertension with right to le…
Specifications and validation of the ACMG/AMP criteria for clinical interpretation of sequence variants in collagen genes associated with joint hypermobility
Deleterious variants in collagen genes are the most common cause of hereditary connective tissue disorders (HCTD). Adaptations of the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) criteria are still lacking. A multidisciplinary team was set up for developing specifications of the ACMG/AMP criteria for COL1A1, COL1A2, COL2A1, COL3A1, COL5A1, COL5A2, COL11A1, COL11A2 and COL12A1, associated with various forms of HCTD featuring joint hypermobility, which is becoming one of the most common reasons of referral for molecular testing in this field. Such specifications were validated against 209 variants, and resulted effective for classifying as p…
Case report: Novel compound heterozygosity for pathogenic variants in MED23 in a syndromic patient with postnatal microcephaly
Biallelic loss-of-function variants in MED23 cause a recessive syndromic intellectual disability condition with or without epilepsy (MRT18). Due to the small number of reported individuals, the clinical phenotype of the disorder has not been fully delineated yet, and the spectrum and frequency of neurologic features have not been fully characterized. Here, we report a 5-year-old girl with compound heterozygous for two additional MED23 variants. Besides global developmental delay, axial hypotonia and peripheral increased muscular tone, absent speech, and generalized tonic seizures, which fit well MRT18, the occurrence of postnatal progressive microcephaly has been here documented. A retrospe…
Cutis verticis gyrata and Noonan syndrome: report of two cases with pathogenetic variant in SOS1 gene
Abstract Background Noonan and Noonan-like syndromes are multisystem genetic disorders, mainly with autosomal dominant trasmission, caused by mutations in several genes. Missense pathogenetic variants of SOS1 gene are the second most common cause of Noonan syndrome (NS) and account approximately for 13% to 17% of cases. Subjects carrying a pathogenetic variant in SOS1 gene tend to exhibit a distinctive phenotype that is characterized by ectodermal abnormalities. Cutis verticis gyrata (CVG) is a rare disease, congenital or acquired, characterized by the redundancy of skin on scalp, forming thick skin folds and grooves of similar aspect to cerebral cortex gyri. Several references in the liter…