Rosanna Rinaldi

Screening of mutations in the CFTR gene in 1195 couples entering assisted reproduction technique programs

Genetic testing of the cystic fibrosis transmembrane conductance (CFTR) gene is currently performed in couples undergoing assisted reproduction techniques (ART), because of the high prevalence of healthy carriers in the population and the pathogenic relationship with congenital bilateral absence of vas deferens (CBAVD). However, discordant data have been reported concerning the usefulness of this genetic test in couples with no family history of cystic fibrosis (CF). In this study, we report the results of CFTR molecular screening in 1195 couples entering ART. Genetic testing was initially carried out in a single partner of each couple. CFTR mutations were detected in 55 subjects (4.6%), a percentage that overlaps with the one reported in the general population. However, significantly higher frequencies of were found in CBAVD individuals (37.5%) and in males with nonobstructive azoospermia (6.6%). The 5T allele was found in 78 patients (6.5%). This figure was again significantly different in males with nonobstructive-azoospermia (9.9%) and in those with CBAVD (100%). All together, 139 subjects (11.6%) had either a CFTR mutation or the 5T allele. Subsequent molecular analysis of their partners disclosed a CFTR mutation or 5T allele in nine cases (6.5%). However, none of these couples had CFTR alterations in both members, a CFTR mutation being invariably present in one partner and the 5T allele in the other. In order to improve genetic counselling of these couples, the TG-M470V-5T association was analyzed, and a statistically significant relationship between 12TG-V470 and CBAVD was detected.

Antenatal presentation of the oculo-auriculo-vertebral spectrum (OAVS)†

We describe a fetus with abnormal ultrasound (US) imaging at 20 weeks showing hydrocephalus and radial aplasia. Post‐mortem examination followed pregnancy termination and confirmed the diagnosis of oculo‐auriculo‐vertebral spectrum (OAVS). To delineate the pattern of prenatal features in OAVS, we reviewed 20 published fetuses showing abnormal US and/or magnetic resonance imaging. Gestational age at diagnosis ranged from 14 to 34–35 weeks. Cephalic abnormalities were found in only 52.4% (i.e., micro/anophthalmia, ear anomalies, hemifacial microsomia, and facial cleft). CNS defects occurred in 47.6% (i.e., hydrocephalus, occipital encephalocele, cerebellar hemisphere/vermis hypoplasia, and lipoma of the corpus callosum), together with abnormal amniotic fluid volume (AFV), either poly‐ or oligohydramnios. Nineteen percent had congenital heart disease, mainly atrioventricular septal defect. Hydroureteronephrosis, radial aplasia, lung, and kidney agenesis were additional findings. Recurrent patterns of anomalies included multiple asymmetric facial lesions (i.e., hemifacial microsomia, ipsilateral micro/anophthalmia, malformed ear) and CNS (particularly hydrocephalus) plus AFV abnormalities. In addition, prognosis of prenatally detected OAVS patients resulted more severe than generally observed in this condition.

VACTERL association and maternal diabetes: A possible causal relationship?

BACKGROUND Some factors(s)/features(s) of maternal insulin-dependent diabetes mellitus are considered common human teratogens. Although the variable association of cardiac, renal, and skeletal anomalies are commonly observed in infants from diabetic mothers, the relationship between VACTERL (i.e., the association of vertebral and cardiac defects, tracheo-esophageal fistula, renal/radial malformations, and other limb anomalies) and maternal diabetes has not been sufficiently emphasized in the literature. CASE We report on a 3-year-old boy presenting with a constellation of blastogenetic malformations strongly suggestive of VACTERL association. His mother was affected by insulin-dependent diabetes since she was 7 years old and pregnancy history disclosed very high glucose and HbA1c levels, especially during the first 2 gestational months. CONCLUSIONS In an attempt to properly counsel the parents, we reviewed the literature and identified four additional patients with VACTERL and first trimester exposure to maternal diabetes mellitus. Although this evidence does not strongly support a causal relationship between these two conditions, additional arguments may substantiate this hypothesis. The pathogenesis of diabetic embryopathy in relation to the VACTERL phenotype is also discussed.

Clinical phenotype and molecular characterization of 6q terminal deletion syndrome: Five new cases

Mental retardation, facial dysmorphisms, seizures, and brain abnormalities are features of 6q terminal deletions. We have ascertained five patients with 6q subtelomere deletions (four de novo, one as a result of an unbalanced translocation) and determined the size of the deletion ranging from 3 to 13 Mb. Our patients showed a recognizable phenotype including mental retardation, characteristic facial appearance, and a distinctive clinico‐neuroradiological picture. Focal epilepsy with consistent electroencephalographic features and with certain brain anomalies on neuroimaging studies should suggest 6q terminal deletion. The awareness of the distinctive clinical picture will help in the diagnosis of this chromosomal abnormality.

Tibial developmental field defect is the most common lower limb malformation pattern in VACTERL association

VACTERL association is one of the most common recognizable patterns of human malformation and has been recently defined as a multiple polytopic developmental field defect. Limb anomalies are a key component of this condition and characteristically reflect perturbation of radial ray development. However, the pattern of appendicular malformations in VACTERL association is wider and includes a broad spectrum of additional and apparently nonspecific anomalies. We report on the sporadic case of a 4–10/12‐year‐old boy presenting with multiple costovertebral defects, dextrocardia, bilateral radial ray hypo/aplasia, unilateral kidney agenesis and anal atresia. Homolaterally to the more severe radial ray defect and kidney aplasia, he also has a complex lower limb malformation, consisting of distal tibial aplasia, clubfoot, hallucal deficiency and preaxial polydactyly. Literature review identifies 24 additional patients with VACTERL manifestations and lower limb malformations (excluding cases with isolated secondary deformations). Tibial hypo/aplasia with or without additional tibial field defects, reported in about 2/3 (68%) of the patients, represents the most common finding, while involvement of the fibular ray is rare (20%) and very often accompanies tibial anomalies. The relatively high frequency of tibial ray anomalies in VACTERL patients could easily be explained by the principle of homology of the developmental field theory. Careful search of lower limb anomalies of the “tibial type” is, therefore, indicated in all patients with multiple polytopic developmental field defects.

Cytogenetic and molecular characterization of a de novo 4q24qter duplication and correlation to the associated phenotype

We report on a newborn with severe psychomotor retardation, minor anomalies, congenital heart defects, thumb and urogenital abnormalities. Cytogenetic analysis showed a 4q24qter duplication, never described before, as the result of a de novo t(4;14). The extension of the duplicated 4q region was defined by FISH using YAC probes. The breakpoint was localized between 106.3cM (YAC 800f2, D4S1572) and 111 cM (YAC 744e4, D4S1564). Comparing our patient with those previously reported in literature, we observed some features mature frequently reported in these patients: psychomotor retardation, retromicrognathia, low set and/or malformed ears and some more specific traits: congenital cardiac defects, hypoplastic thumb and urogenital abnormalities.

Clinical Management and Molecular Cytogenetic Characterization in a 45,X/46,X,idic(Yp) Patient With Severe Hypospadia

Cryptorchidism and proximal hypospadia in a newborn are highly suspicious for an intersex disorder, and proper investigations should be planned immediately after birth. In some hypospadic patients, the presence of a palpable gonad in the scrotum may induce to assign the male sex, whereas the anatomy of internal and external genitalia could be extremely complex, requiring an accurate evaluation before any definitive attribution of gender. The authors present a case of an infant, referred to the hospital for surgical treatment of a proximal hypospadia, who showed ambiguous external genitalia, absence of the right gonad, a partially dysgenetic left testis, and presence of both müllerian and wolffian structures. Cytogenetic analysis detected a mosaicism with a cell line showing an isodicentric Yp chromosome and a second one, a 45, X chromosomal complement. Because the baby had been assigned previously to male gender, he underwent a staged masculinizing correction of the genital anomalies. The authors discuss the necessity of a careful evaluation of these patients at birth by a multispecialistic team, for appropriate sex assignment and for the assessment of the risk of neoplastic degeneration.

De novo pure 12q22q24.33 duplication: First report of a case with mental retardation, ADHD, and Dandy-Walker malformation†

We present a patient with a de novo 12q nonmosaic pure duplication characterized by multiple minor anomalies and Dandy–Walker malformation. A neurological and behavioral assessment revealed psychomotor retardation and attention deficit/hyperactivity disorder (ADHD), with neurobehavioral abnormalities (auto‐ and heteroaggressive behavior). Fluoxetine therapy in this case markedly improved the neurobehavioral profile, with a decreased level of aggression. To define the extension of the duplicated region, we performed FISH analyses by using YAC probes. The analyses revealed a tandem duplication of the 12q22q24.33 region, with the proximal breakpoint located between 96.5 and 97.6 cM and the distal one between 154 and 161 cM. This is the first case of pure de novo duplication involving the 12q22q24.33 region. To better define the clinical phenotype associated with 12q partial duplication, we compared our case with the four patients with similar pure duplications previously described.

Phacomatosis cesioflammea with unilateral lipohypoplasia.

Phacomatosis cesioflammea is characterized by the co‐existence of a large nevus cesius (i.e., aberrant Mongolian spot, or nevus fuscocoeruleus) and an extensive nevus flammeus (i.e., port‐wine stain). This sporadic genetic skin disorder represents a particular type of phacomatosis pigmentovascularis, a group of disorders that may reflect twin spotting. We report on a 28‐year‐old woman with aberrant Mongolian spots, bilateral melanosis bulbi, and systematized nevus flammeus partly intermingled with nevus anemicus. Moreover, pronounced lipohypoplasia of the right buttock and thigh as well as hypoplasia of the right breast are present. This anomaly of fatty tissue has not previously been reported in phacomatosis cesioflammea and further expands the clinical spectrum of this mosaic disorder. The patchy distribution of lipohypoplasia and its spatial relationship with vascular lesions strongly support the hypothesis of a postzygotic recombination event.

Juvenile macular dystrophy and forearm pronation-supination restriction presenting with features of distal arthrogryposis type 5†

The distal arthrogryposes are a heterogeneous group of conditions characterized by congenital contractures of hands and feet, and autosomal dominant inheritance. The concurrence of ophthalmoplegia and additional ocular findings distinguish distal arthrogryposis type 5 (DA5). This rare subtype has been described in 33 patients to date and its clinical spectrum of physical findings is still poorly understood. We report on a family with three individuals with DA5. The index case came to our attention because of restricted forearm pronation‐supination and juvenile macular dystrophy. Further examination revealed short stature, firm muscles, stiff spine with lumbar hyperlordosis, generalized mild limitation of the large joints, external rotation of the hips, unilateral ptosis, exophoria, and abnormal photopic and scotopic responses on electroretinogram testing. However, there was no overt evidence of contractures of the distal joints. Examination of other affected family members revealed restricted range of movement of the small joints together with ulnar deviation of the fingers, and clarified the diagnosis. Our observations suggest that DA5 may have a very mild musculoskeletal phenotype and it should be considered in the differential of congenital contracture syndromes even in the absence of obvious distal joint involvement. Our observations also suggest that fundoscopy and ocular electrophysiological studies might be helpful in the evaluation of patients with otherwise unclassified distal arthrogryposes. Am. J. Med. Genet.