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Biomedical subjects

A Giannotti

Publications and source records attributed to A Giannotti.

At least 73 records · Page 4Linked to original sources
PubMed1997

Tricuspid atresia and 22q11 deletion.

Tricuspid atresia has not been reported in 22q11 microdeletions causing DiGeorge and velo-cardio-facial syndromes. We investigated the prevalence of 22q11 hemizygosity in 26 children with tricuspid atresia. Fluorescent hybridization with the Sc11.1 probe demonstrated a 22q11 microdeletion in 2 patients, one with and another without transposition of the great arteries. Both deletion patients had minor facial anomalies characteristic of DiGeorge syndrome. The present observations suggest that tricuspid atresia should be included in the list of cardiac malformations seen in del22q11 syndromes.

Adult↗
PubMed1997

Conotruncal heart defect/microphthalmia syndrome: delineation of an autosomal recessive syndrome.

We report on three sibs born to healthy parents, one livebirth and two terminated pregnancies, presenting with a malformation complex characterised by conotruncal heart defect (CTHD), microphthalmia, genital anomalies, and facial dysmorphism. The recurrence of the association of CTHD, particularly truncus arteriosus, and microphthalmia in sibs has previously been reported in rare instances, but a correlation between the single descriptions has never been noted. CTHDs are included among the cardiac malformations characteristically associated with the group of syndromes caused by the microdeletion of chromosome 22q11, but no detectable hemizygosity has been found in our family. An autosomal recessive gene seems to be involved in syndromic patients with the combination of CTHD and microphthalmia. The map location of this gene is at present unknown, but autosomal recessive inheritance must be considered in genetic counselling of families with children presenting with this malformation complex.

Abnormalities, Multiple↗
PubMed1997

Radial aplasia and chromosome 22q11 deletion.

We report on a neonate with deletion 22q11 (del22q11) presenting with facial dysmorphism, ocular coloboma, congenital heart defect, urogenital malformations, and unilateral radial aplasia. This malformation complex includes features frequently occurring in velocardiofacial syndrome as well as findings described in the CHARGE and VACTERL associations. To our knowledge, the present case is the first report of radial aplasia in del22q11. This observation further supports and extends the clinical variability of del22q11.

Abnormalities, Multiple↗
PubMed1997

Recurrence risk figures for isolated tetralogy of Fallot after screening for 22q11 microdeletion.

Isolated tetralogy of Fallot (TF) has a multifactorial mode of inheritance in most cases, and recurrence risk rates of 2.5-3% have been attributed to first degree relatives of an affected child. In a subgroup of patients with a strong family history, the transmission of a monogenic trait has been suspected. Microdeletion 22q11 (del(22q11)) can cause TF in the setting of DiGeorge and velocardiofacial syndromes, and has also been related to familial conotruncal cardiac defects. Empirical risk figures in families after exclusion of del(22q11) have never been calculated. We have investigated the overall occurrence of congenital heart defect (CHD) in relatives of 102 patients with isolated non-syndromic TF previously screened for del(22q11). Our results show that the frequency of CHD is 3% in sibs, 0.5% in parents, 0.3% in grandparents, 0.2% in uncles or aunts, and 0.6% in first cousins. The recurrence risk rate for sibs in our series is the same as that previously estimated, indicating that after exclusion of patients with del(22q11) genetic counselling to patients with isolated TF should not be modified. A high concordance rate among our affected sibs has been documented. Gene(s) different from those located on chromosome 22q11 must be involved in causing familial aggregation of non-syndromic TF in these cases.

Adolescent↗
PubMed1997

Two newborns with chromosome 4 imbalances: deletion 4q33-->q35 and ring r(4)(pterq35.2-qter).

Two patients are reported who presented with 4q deletion and r(4), respectively. Cytogenetic and FISH analysis defined the breakpoints respectively at bands 4q33-->q35 proximal to the telomere, and 4pter and 4q35.2 qter. Moreover in both cases rearranged chromosomes maintained telomeric sequences. The first patient showed some clinical features of deletion 4q and a pointed 5th finger, a characteristic finding in deletion 4q31-->qter. The second patient had mild dysmorphism associated with growth retardation.

Chromosome Deletion↗
PubMed1996

Associated cardiac anomalies in isolated and syndromic patients with tetralogy of Fallot.

To detect in children with tetralogy of Fallot (ToF) the prevalence of associated cardiac anomalies in syndromic and isolated cases, the additional cardiac defects of 150 consecutive patients with ToF (102 isolated and 48 syndromic cases) were evaluated by review of echocardiographic, angiocardiographic, and surgical reports. Syndromic patients were classified into groups with branchial arch defects, Down syndrome, and other genetic conditions. ToF is significantly associated with additional cardiac malformations in patients with branchial arch (11 of 21, p <0.01) and Down (10 of 20, p <0.0001) syndromes. The subarterial ventricular septal defect with deficiency of the infundibular septum (4 of 21, p <0.01) and the right aortic arch (6 of 21, p <0.05) were prevalent in patients with branchial arch syndromes, whereas atrioventricular canal (10 of 20, p <0.0001) was associated with ToF in patients with Down syndrome. Peculiar anatomic cardiac patterns are present in children with ToF and may alert the cardiologist to look at additional cardiac anomalies. Moreover, the presence of some associated cardiac anomalies may suggest careful clinical evaluation for genetic syndromes.

Adolescent↗
PubMed1996

Apparent preferential loss of heterozygosity at TSC2 over TSC1 chromosomal region in tuberous sclerosis hamartomas.

To investigate the molecular mechanisms of tuberous sclerosis (TSC) histopathologic lesions, we have tested for loss of heterozygosity the two TSC loci (TSC1 and TSC2) and seven tumor suppressor gene-containing regions (TP53, NF1, NF2, BRCA1, APC, VHL, and MLM) in 20 hamartomas from 18 TSC patients. Overall, eight angiomyolipomas, eight giant cell astrocytomas, one cortical tuber, and three rhabdomyomas were analyzed. Loss of heterozygosity at either TSC locus was found in a large fraction of the informative patients, both sporadic (7/14) and familial (1/4). Interestingly, a statistically significant preponderance of loss of heterozygosity at TSC2 was observed in the sporadic group (P < 0.01). Among the possible explanations considered, the bias in the selection for TSC patients with the most severe organ impairment seems particularly appealing. According to this view, a TSC2 defect might confer a greater risk for early kidney failure or, possibly, a more rapid growth of a giant cell astrocytoma. None of the seven antioncogenes tested showed loss of heterozygosity, indicating that the loss of either TSC gene product may be sufficient to promote hamartomatous cell growth. Finally, the observation of loss of heterozygosity at different markers in an astrocytoma and in an angiomyolipoma from the same patient might suggest the multifocal origin of the second-hit mutation.

Chromosome Deletion↗
PubMed1996

Orocardiodigital syndrome: an oral-facial-digital type II variant associated with atrioventricular canal.

We report on a patient with a constellation of anomalies including hamartomas of the tongue, polysyndactyly, and atrioventricular canal. A similar association has been previously described by Orstavik et al in two sibs. The clinical spectrum of the oralfacial-digital syndrome (OFDS) type II includes all these features. In particular, congenital heart defect, mainly atrioventricular canal, has been described in a few cases. It has been previously suggested that these latter patients may be affected by a variant of OFDS type II. We propose to distinguish this orocardiodigital variant and point out the association of the syndrome with atrioventricular canal.

Adult↗