Hereditary motor and sensory neuropathy (HMSN) IA, developmental delay and autism related disorder in a boy with duplication (17)(p11.2p12)

We present a 6-year-old boy with moderate developmental delay, gait disturbance, autism related disorder and mild dysmorphic features. He was seen for evaluation of his retardation since the age of 2.8 years. At first sight, a cytogenetic analysis showed a normal 46,XY karyotype. Neurological examination at the age of 5.5 years revealed a motor and sensory polyneuropathy. A quantitative Southern blot with probes PMP22 and VAW409 specific for Charcot-Marie-Tooth type 1 (CMT1) disclosed a duplication which confirmed the diagnosis HMSN Ia. Subsequently, GTG banded metaphases were re-evaluated and a small duplication 17p was seen on retrospect. Additional FISH with probe LSISMS (Vysis) specific for the Smith-Magenis region at 17p11.2 again showed a duplication. Both parents had a normal karyotype and the duplication test for CMT1 showed normal results for both of them. The boy had a de novo 46,XY,dup(17)(p11.2p12) karyotype. The present observation confirms previous findings of mild psychomotor delay, neurobehavioural features and minor craniofacial anomalies as the major phenotypic features of dup(17)(p11.2) and dup(17)(p11.2p12); in cases of duplications comprising the PMP22 locus HMSN1 is associated. A recognizable facial phenotype emerges characterized by a broad forehead, hypertelorism, downslant of palpebral fissures, smooth philtrum, thin upper lip and ear anomalies.     

A patient with hypopituitarism and isochromosome 18q mosaicism

AIMS: Patients with isochromosome 18 [i(18q)] have features of both trisomy 18 and deletion of 18p [del(18p)] syndromes. Although, hypopituitarism has been reported in patients with del(18p) syndrome, it has not been described in patients with i(18q) syndrome previously. We describe a case with i(18q)/del(18p) mosaicism associated with a novel finding of hypopituitarism. METHODS: Clinical characteristics of the patient have been discussed in the light of the literature. RESULTS: The patient had dysmorphic findings that are predominantly seen in del(18p) syndrome such as low nasal bridge, wide mouth, large ears, high forehead, hypopigmentation, upturned nostrils and hypopituitarism (TSH, ACTH, and GH deficiencies, and pituitary hypoplasia on magnetic resonance imaging). In addition, she also had upturning of upper lip and seizures, which are features of trisomy 18 syndrome. CONCLUSIONS: In agreement with the previous clinical reports, this case further supports the presence of a factor, which is involved in pituitary development and/or function, on the short arm of chromosome 18.     

Inherited ring chromosome 8 without loss of subtelomeric sequences

We report the first case of inherited ring chromosome 8 syndrome without loss of subtelomeric sequences. The proband is a 6 1/2-year-old boy with short stature, microcephaly, mild mental retardation, and behavioral problems including hyperactivity and attention deficit. His mother presented the same physical features but intelligence was normal. Family history also revealed an uncle and a grandmother, with short stature and microcephaly. Moderate mental retardation was reported in the uncle. Karyotypes and fluorescence in situ hybridization (FISH) analyses were performed on peripheral blood lymphocytes for both child and mother. The child's karyotype was reported as 46,XY,r(8)(p23q24.3)[24]/45,XY,-8[2] and the mother's karyotype 46,XX,r(8)(p23q24.3)[22]/45,XX,-8[2]/47,XX,r(8)(p23q24.3), +r(8)(p23q24.3)[1]. FISH studies showed no deletion of subtelomeric sequences for both child and mother indicating that no or little chromosomal euchromatic material has been deleted. These findings indicate that ring chromosome 8 without loss of subtelomeric sequences can be inherited and that carriers in a same family present with cognitive function ranging from mild mental retardation to normal intelligence.     

A case of (13q;18q) translocation with proximal 13q monosomy

Summary A case of partial monosomy of the 13p terminal to 13q12, associated with a de novo 13/18 translocation, is reported. The symptoms appeared to be derived from both 18q- and partial monosomy 13, the latter giving rise to: high arched palate, epicanthus, antimongolian slant, small eye fissure, flat nasal bridge, hypoplastic helix, and large clitoris. Serum Ig-A and Ig-M levels were normal in our case.     

Partial trisomy 10q

Summary Five cases from two nonrelated families with partial trisomy 10q due to a reciprocal translocation t(10;17)(q25;p13) and t(10;11)(q24;q23), respectively, are reported. The phenotypic findings are compared with those of 17 previously published cases; the clinical data justify the conclusion that cases with trisomy 10q show a specific syndrome of mental retardation and malformation characterized by psychomotor retardation, growth retardation, hypotonia, high forehead, flat face, fine and arched eyebrows, antimongoloid slant of the eyes, narrow palpebral fissures, hypertelorism, short nose, bowshaped mouth, short neck, (kypho)scoliosis, and in some cases microcephaly.     

Loeys-Dietz syndrome type I and type II: clinical findings and novel mutations in two Italian patients

Sheldon-Hall syndrome (SHS) is a rare multiple congenital contracture syndrome characterized by contractures of the distal joints of the limbs, triangular face, downslanting palpebral fissures, small mouth, and high arched palate. Epidemiological data for the prevalence of SHS are not available, but less than 100 cases have been reported in the literature. Other common clinical features of SHS include prominent nasolabial folds, high arched palate, attached earlobes, mild cervical webbing, short stature, severe camptodactyly, ulnar deviation, and vertical talus and/or talipes equinovarus. Typically, the contractures are most severe at birth and non-progressive. SHS is inherited in an autosomal dominant pattern but about half the cases are sporadic. Mutations in either MYH3, TNNI2, or TNNT3 have been found in about 50% of cases. These genes encode proteins of the contractile apparatus of fast twitch skeletal muscle fibers. The diagnosis of SHS is based on clinical criteria. Mutation analysis is useful to distinguish SHS from arthrogryposis syndromes with similar features (e.g. distal arthrogryposis 1 and Freeman-Sheldon syndrome). Prenatal diagnosis by ultrasonography is feasible at 18–24 weeks of gestation. If the family history is positive and the mutation is known in the family, prenatal molecular genetic diagnosis is possible. There is no specific therapy for SHS. However, patients benefit from early intervention with occupational and physical therapy, serial casting, and/or surgery. Life expectancy and cognitive abilities are normal.     

Additional chromosome in a child as a result of a balanced reciprocal translocation t(12;18)(p13;q12) in his mother's karyotype

In this case report we present a child with an additional chromosome in the karyotype. The karyotypes of the boy and his parents were analyzed by use of a conventional banding technique (GTG) and fluorescence in situ hybridization (FISH). Probes painting whole chromosomes 12 and 18 were used in FISH. Cytogenetic examination of the parents revealed that his mother was carrying balanced reciprocal translocation between chromosomes 12 and 18. Her karyotype was described as 46,XX,t(12;18)(p13;q12). Father's karyotype was normal, described as 46,XY. The boy's karyotype was defined as 47,XY,+der(18)t(12;18)(p13;q12). The additional chromosome appeared probably due to 3:1 meiotic disjunction of the maternal balanced translocation, known as tertiary trisomy. The mother displayed a normal phenotype and delivered earlier a healthy child. However, the boy with the unbalanced karyotype shows multiple congenital abnormalities.     

Tetrasomy of the short arm of human chromosome 18: cytogenetics and phenotypic disorders

Two mentally retarded girls with a small metacentric nonsatellite extrachromosome were examined. Probands were found to share many clinical features: asthenic constitution, microcephalia, low-set malformed ears, high arched palate, long fingers and toes, a wide gap between first and second toes, clinodactyly of the 1st and 5th fingers, scoliosis. The extrachromosome was unequivocally interpreted as an isochromosome for the short arm of chromosome 18. Review of 12 i (18p) cases permits characterizing a syndrome of tetrasomy 18p.     

Wolf-Hirschhorn and Cri du Chat syndromes resulting from familial translocations: 3 further examples of the Bp monosomy epistatic effect

Two malformed newborns with the typical Wolf-Hirschhorn syndrome (WHS) resulting from familial balanced translocations t(4;11)(p153;p154) and t(4;18)(p152;q23) respectively, are presented. A third child with the Cri du Chat syndrome and der(5), t(2;5)(q333;p141) is reported. These three cases give further support to the epistatic hypothesis at the chromosomal level of the Bp monosomies over other partial autosomal trisomic syndromes.     

Small marker chromosomes in two patients with segmental aneusomy for proximal 17p

We report a nine-year-old girl (patient 1934) and a five-year-old boy (patient 2170) with small, de novo supernumerary marker chromosomes (SMCs) derived from proximal 17p. The clinical features of patient 1934 include developmental delay, triangular face, prominent forehead, low set ears, dental abnormalities, a high arched palate, long, flexible fingers, and joint laxity. Patient 2170 is affected with developmental delay, oral-motor dyspraxia/verbal apraxia, thick upper and lower lips, bilateral fifth finger clinodactyly, joint laxity and mild hypotonia. G-banded chromosome analysis of patient 1934 revealed mosaicism for a SMC in 72% of peripheral lymphocytes analyzed, whereas analysis of patient 2170 identified a smaller SMC present in 100% of cells analyzed. Fluorescence in situ hybridization (FISH) studies demonstrated that both of the SMCs derived from 17p10-p11.2. Using FISH and array-CGH analysis, the proximal breakpoints mapped within the centromere and the distal breakpoints were both located within the Smith-Magenis syndrome (SMS) common deletion region. We compare the clinical characteristics of our patients with those previously reported to have either SMC including 17p or duplications of proximal 17p in an effort to further delineate the phenotype of trisomy 17p10-p11.2 and to elucidate genotype-phenotype correlations.     

Paracentric inversion in the short arm of chromosome 1. Report of a family and review of the literature

In general, carriers of paracentric inversions are phenotypically normal, although individual reports describe like occurrence of infertility, miscarriages and mental retardation in inversion carriers. We present a family with paracentric inversion of 1p [karyotype: 46,XY/XY, inv(1)(p13.2p36.2)] in 7 of the 12 investigated family members. The index patient, a four year-old boy was referred for motor and mental retardation. The possible relationship between the paracentric inversion and the MR/MCA syndrome in the index patient of this family is briefly discussed.     

Emanuel syndrome due to unusual segregation of paternal origin

Emanuel syndrome is an inherited chromosomal abnormality resulting from 3:1 meiotic segregation from parental balanced translocation carrier t(11;22)(q23;q11), mostly of maternal origin. It is characterized by mental retardation, microcephaly, preauricular tag or sinus, ear anomalies, cleft or high arched palate, micrognathia, congenital heart diseases, kidney abnormalities, structural brain anomalies and genital anomalies in male. Here in, we describe a female patient with supernumerary der(22) syndrome (Emanuel syndrome) due to balanced translocation carrier father t(11;22) (q23;q11). She was mentally and physically disabled and had most of the craniofacial dysmorphism of this syndrome. Our patient had cleft palate, maldeveloped corpus callosum and hind brain with normal internal organs. Additionally, arachnodactyly, hyperextensibility of hand joints, abnormal deep palmar and finger creases, extra finger creases and bilateral talipus were evident and not previously described with this syndrome. Cytogenetic analysis and FISH documented that the patient had both translocation chromosomes plus an additional copy of der(22) with karyotyping: 47,XX,t(11; 22)(q23;q11),+der(22)t(11;22)(q23;q11). We postulated that this rare chromosomal complement can arise from; 2:2 segregation in the first meiotic division of the balanced translocation father followed by non-disjunction at meiosis II in the balanced spermatocyte.     

Brown-Vialetto-Van Laere syndrome

Monosomy 18p refers to a chromosomal disorder resulting from the deletion of all or part of the short arm of chromosome 18. The incidence is estimated to be about 1:50,000 live-born infants. In the commonest form of the disorder, the dysmorphic syndrome is very moderate and non-specific. The main clinical features are short stature, round face with short philtrum, palpebral ptosis and large ears with detached pinnae. Intellectual deficiency is mild to moderate. A small subset of patients, about 10–15 percent of cases, present with severe brain/facial malformations evocative of holoprosencephaly spectrum disorders. In two-thirds of the cases, the 18p- syndrome is due to a mere terminal deletion occurring de novo, in one-third the following are possible: a de novo translocation with loss of 18p, malsegregation of a parental translocation or inversion, or a ring chr18. Parental transmission of the 18p- syndrome has been reported. Cytogenetic analysis is necessary to make a definite diagnosis. Recurrence risk for siblings is low in de novo deletions and translocations, but is significant if a parental rearrangement is present. Deletion 18p can be detected prenatally by amniocentesis or chorionic villus sampling and cytogenetic testing. Differential diagnosis may include a wide number of syndromes with short stature and mild intellectual deficiency. In young children, deletion 18p syndrome may be vaguely evocative of either Turner syndrome or trisomy 21. No specific treatment exists but speech therapy and early educational programs may help to improve the performances of the children. Except for the patients with severe brain malformations, the life expectancy does not seem significantly reduced.     

Langer-Giedion syndrome,in a child with complex structural aberration of chromosome 8

A patient with typical features of the Langer-Giedion syndrome (tricho-rhino-phalangeal syndrome, type II) is described. In the karyotype an interstitial deletion of the long arm of chromosome 8 (band 8q22) was observed as the result of a complex rearrangement of chromosomes 1 and 8: 46,XY inv(8)(q23 leads to q242), del(8)(q221 leads to q223), ins(8;1) (q221;p321 p341;q242). Previously reported cases of Langer-Giedion syndrome with deletion of 8q are compared with the present one.     

The spectrum of 4q- syndrome illustrated by a case series

Deletions of the long arm of chromosome 4 detectable by cytogenetic analysis (standard karyotyping), fluorescent in situ hybridisation (FISH), multiplex ligation-dependent probe amplification (MLPA) or comparative genomic hybridisation (CGH) cause 4q- syndrome. Here we describe 3 cases of 4q- syndrome which demonstrate the variations in clinical presentation, diagnosis and prognosis observed in this condition. Patient 1 was a female foetus diagnosed with del(4)(q33) following chorionic villus sampling (CVS) at 14weeks, and the pregnancy was terminated at 18weeks. Patient 2 was a 5-month-old boy with del(4)(q31.3) and complex congenital heart disease. He also had a duplication of chromosome 6p and died of cardiac failure. Patient 3 is a 2-year-old girl with mild dysmorphic features and an interstitial deletion del(4)(q22.1q23). She has no major malformations and only slight developmental delay.     

Do we consider Andermann syndrome in infants with agenesis of corpus callosum

Andermann syndrome is characterized by agenesis of corpus callosum, anterior horn cell disease, a mixed sensory and motor neuropathy, and facial dysmorphism, and is inherited as an autosomal recessive trait. A 7-month-old boy was admitted with developmental retardation. Head control was not gained and he could not sit. He had high arched palate, elongated facies and large angle of the mandible, which were compatible with the Andermann syndrome. Moderate hypotonicity and absent tendon reflexes were also noted. Serum creatine kinase level was normal. Magnetic resonance imaging of the brain showed agenesis of the corpus callosum. Electromyographic examination revealed the presence of both sensory and motor neuropathy. The patient was diagnosed as having the Andermann syndrome according to the clinical and laboratory findings and he is reported due to rare presentation.     

Duplications of chromosome 11p15 of maternal origin result in a phenotype that includes growth retardation

Paternal duplications of distal 11p result in Beckwith Wiedemann syndrome (BWS), whereas maternal duplications have not, to our knowledge, been reported previously in the literature. We present three unrelated patients with maternal duplications of distal 11p. Patient 1 is a 31-year-old female with a de novo inverted duplication of distal 11p, i.e. inv dup del(11)(qter-->p15.5::p15.5-->15.3); this rearrangement was shown to be maternal in origin by microsatellite analysis and methylation-specific polymerase chain reaction. Patient 2 is a 4-year-old female with a derived chromosome 20, which arose from adjacent 1 malsegregation of a maternal t(11;20)(p15.3;q13.33). Patient 3 presented as an intrauterine death with trisomy for the majority of chromosome 11p as a result of 3:1 segregation of a maternal t(11;15)(p11.2;q11.2). In view of the imprinted status of this region, it is pertinent that none of our patients showed features of BWS; indeed, all had growth retardation, in contrast to the overgrowth characteristic of BWS. It is of note that, of the living patients, Patient 1 went into early puberty at 9.5 years and Patient 2 showed breast development in infancy. Both patients shared some dysmorphological features, namely short palpebral fissures, a prominent nasal tip, a short philtrum and 5th finger clinodactyly.     

Microphthalmia with linear skin defects syndrome in a mosaic female infant with monosomy for the Xp22 region: molecular analysis of the Xp22 breakpoint and the X-inactivation pattern

This paper describes a female infant with microphthalmia with linear skin defects syndrome (MLS) and monosomy for the Xp22 region. Her clinical features included right microphthalmia and sclerocornea, left corneal opacity, linear red rash and scar-like skin lesion on the nose and cheeks, and absence of the corpus callosum. Cytogenetic studies revealed a 45,X[18]/46,X,r(X)(p22q21) [24]/46,X,del(X)(p22)[58] karyotype. Fluorescence in situ hybridization analysis showed that the ring X chromosome was positive for DXZ1 and XIST and negative for the Xp and Xq telomeric regions, whereas the deleted X chromosome was positive for DXZ1, XIST, and the Xq telomeric region and negative for the Xp telomeric region. Microsatellite analysis for 19 loci at the X-differential region of Xp22 disclosed monosomy for Xp22 involving the critical region for the MLS gene, with the breakpoint between DXS1053 and DXS418. X-inactivation analysis for the methylation status of the PGK gene indicated the presence of inactive normal X chromosomes. The Xp22 deletion of our patient is the largest in MLS patients with molecularly defined Xp22 monosomy. Nevertheless, the result of X-inactivation analysis implies that the normal X chromosomes in the 46,X,del(X)(p22) cell lineage were more or less subject to X-inactivation, because normal X chromosomes in the 45,X and 46,X,r(X)(p22q21) cell lineages are unlikely to undergo X-inactivation. This supports the notion that functional absence of the MLS gene caused by inactivation of the normal X chromosome plays a pivotal role in the development of MLS in patients with Xp22 monosomy. Received: 16 December 1997 / Accepted: 25 February 1998     

Trisomy 11p15 and Beckwith-Wiedemann syndrome. Report of two new cases

An association between trisomy 11p15 and Beckwith-Wiedemann syndrome is described in two brothers. The first presented at birth with gigantism and macroglossia, umbilical hernia and abdominal distention, hypoglycemia and atresia of the pulmonary artery, leading to the diagnosis of Beckwith-Wiedemann syndrome. Facial dysmorphism also included: a hypoplastic midface, hypertelorism, and a short nose with a flattened bridge. The karyotype showed a trisomy 11p15 with a monosomy 18p11, due to a t(11;18)(p154;p111)pat. His brother, born a year later, showed the same signs. The association between trisomy 11p15 and Beckwith-Wiedemann syndrome is in certain cases well established.     

Characterization of Potocki-Lupski syndrome (dup(17)(p11.2p11.2)) and delineation of a dosage-sensitive critical interval that can convey an autism phenotype

The duplication 17p11.2 syndrome, associated with dup(17)(p11.2p11.2), is a recently recognized syndrome of multiple congenital anomalies and mental retardation and is the first predicted reciprocal microduplication syndrome described--the homologous recombination reciprocal of the Smith-Magenis syndrome (SMS) microdeletion (del(17)(p11.2p11.2)). We previously described seven subjects with dup(17)(p11.2p11.2) and noted their relatively mild phenotype compared with that of individuals with SMS. Here, we molecularly analyzed 28 additional patients, using multiple independent assays, and also report the phenotypic characteristics obtained from extensive multidisciplinary clinical study of a subset of these patients. Whereas the majority of subjects (22 of 35) harbor the homologous recombination reciprocal product of the common SMS microdeletion (~3.7 Mb), 13 subjects (~37%) have nonrecurrent duplications ranging in size from 1.3 to 15.2 Mb. Molecular studies suggest potential mechanistic differences between nonrecurrent duplications and nonrecurrent genomic deletions. Clinical features observed in patients with the common dup(17)(p11.2p11.2) are distinct from those seen with SMS and include infantile hypotonia, failure to thrive, mental retardation, autistic features, sleep apnea, and structural cardiovascular anomalies. We narrow the critical region to a 1.3-Mb genomic interval that contains the dosage-sensitive RAI1 gene. Our results refine the critical region for Potocki-Lupski syndrome, provide information to assist in clinical diagnosis and management, and lend further support for the concept that genomic architecture incites genomic instability.