16q21 is critical for 16q deletion syndrome

A 1-year-old girl with an interstitial deletion of the long arm of chromosome 16 is reported. She was characterized by a distinct craniofacial dysmorphism, meningoencephalocele, mild hydrocephalus, short neck, broad great toes and abnormally positioned toes. High resolution GTG and RBG banding analyses revealed a karyotype: 46,XX,del(16) (q13q22) de novo. An analysis of the smallest region of overlap revealed that the critical band region for 16q deletion syndrome is 16q21.     

Interstitial deletion of chromosome 16q: 16q22 is critical for 16q- syndrome.

Partial deletion of 16q is rare; to our knowledge only 12 cases have been published. Fryns et al. [Hum Genet 38:343-346, 1977] described the first of these cases and proposed a new clinical entity. Our patient was a girl and had many minor anomalies of the kind often observed in 16q- syndrome. Severe failure to thrive due to emesis and diarrhea were also observed. High resolution banding methods showed that the chromosome constitution of the patient was 46,XX,del(16)(q22.1q22.3). This suggests that 16q22 is critical for the syndrome.     

Interstitial deletion of the long arm of chromosome 4, del(4)(q28→q31.3)

Interstitial deletions of the long arm of chromosome 4 are rare. Different breakpoints are involved. Only one of the patients had a very similar deletion to that of the present case. Both had low birth weight at term; weight, length and head circumference less than the third centile; epicanthic folds; apparently low-set abnormal ears; broad nasal bridge; micrognathia; hypoplastic nails; delayed psychomotor development; and mild mental retardation. © 1995 Wiley-Liss, Inc.     

Interstitial deletion 4q and Rieger syndrome

In a 9-year-old girl, the diagnosis of the Rieger syndrome, an autosomal dominant disorder of variable expressivity, was established on the basis of characteristic congenital ocular and dental anomalies. Cytogenetic analysis revealed a de novo interstitial deletion of 4q.     

Interstitial deletion of 10q: Clinical features and literature review

We report on a patient with interstitial deletion of 10q and compare her to 8 previously described patients, 2 of whom have chromosomal breakpoints similar to our patient. Minor anomalies including broad forehead, hypertelorism, strabismus, prominent philtrum, and “dysplastic” pinnae are present in our patient. Psychomotor retardation and hypotonia are universal findings in 10q interstitial deletion. Growth retardation, not present in our patient, is seen in some. These clinical findings are sufficiently distinct to suggest early chromosome studies. © 1992 Wiley-Liss, Inc.     

Interstitial deletion of the long arm of chromosome 2 in a malformed infant with karyotype 46, XX,del(2) (q31q33)

We describe a malformed newborn girl with an interstitial deletion of the long arm of chromosome 2 (karyotype: 46, XX, del (2) (q31q33)). This is the first report of this particular chromosome abnormality that includes autopsy findings. Comparison with previous cases in the literature suggests that this particular deletion uniformly results in developmental delays, craniofacial changes, and occasionally results in microcephaly, low-set ears, and hand and foot abnormalities.     

Reassessment of the 12q15 deletion syndrome critical region

Interstitial deletions of the long arm of chromosome 12 are rare and only few cases have been reported in literature so far, with different phenotypic features related to size and gene content of deleted regions. Five patients reported a 12q15-q21 deletion, sharing a 1.3 Mb small region of overlap (SRO) and presenting with developmental delay, nasal speech and mild dysmorphic features.We identified by microarray analysis a new case of 12q15 deletion. Our patient clinical features allow the refinement of the SRO to CNOT2, KCNMB4, and PTPRB genes, improving genotype-phenotype correlations.     

Two cases of 16q12.1q21 deletions and refinement of the critical region

Interstitial deletions of 16q chromosome including 16q12.1q21 region are very rare, with only three cases reported to date. Main clinical features include dysmorphisms, short stature, microcephaly, eye abnormalities, epilepsy, development delay, intellectual disability, and autism spectrum disorder.We report two independent subjects with 16q12.1q21 deletion syndrome presenting with dysmorphic facial features, developmental delay, strabismus, and aggressive behavior. A minimal region of overlap spanning 1.7 Mb on chromosome 16, including IRX5, GNAO1, and NUDT21 genes was shared among these two cases and those previously reported. This minimal region of overlap suggests the potential pathogenic role of these genes, previously implicated in diseases of the central nervous system.     

Interstitial deletion of chromosome 1 del (1) (q32 q42): case report and review of the literature

We describe the case of a female infant with multiple congenital anomalies who was found to have a de novo distal intestinal del (1) (q32 q42). The clinical features of other reports of similar deletions are briefly reviewed. No characteristic phenotype seems to be as yet definable due to the limited number of cases published.     

De novo 10q22 interstitial deletion

We describe a 4 month old male with a de novo interstitial deletion of chromosome 10q22. His clinical features included growth deficiency, developmental delay, ocular hypertelorism, posteriorly rotated ears, retrognathia, and fifth finger clinodactyly. He later developed dental lamina cysts of the alveolar ridge. To our knowledge, this is the first reported case of an interstitial deletion of 10q22.


Keywords: chromosome 10; interstitial deletion; deletion 10q; multiple congenital anomaly (MCA) syndrome     

Interstitial deletion of long arm of chromosome no. 5 with growth hormone deficiency-an emerging syndrome?

5p-is a well-defined syndrome, but phenotypic correlations of 5q are poorly described in the literature. We present a case of a female child with interstitial deletion in the 5q13.1q15 region. Comparison of the clinical features of this patient with others reported in the literature suggests an emerging clinical syndrome defined by short stature, failure to thrive, mental retardation, slanting palpebral fissures, malformed ears, short neck and depressed nasal bridge. Based on our endocrine testing, we hypothesize that the short stature could be, in part, due to growth hormone deficiency. The recent assignment of growth hormone receptor gene to the short arm of chromosome 5 and the presence of several genes for growth factors and growth factor receptors on 5q raise interesting possibilities for the explanation of short stature in such cases.     

Interstitial deletion of chromosome 1 (q23–25). Report of a case

We describe a 3-month-old female with a de novo interstitial deletion of the long arm of chromosome 1 (1q23–25). Clinical features are failure to thrive, psychomotor retardation, cleft lip and palate, short metacarpals, metatarsals and fingers and a severe congenital heart disease.
The four previously reported patients with the same deletion share with ours the distinctive pattern of anomalies of the face and limbs; therefore, it seems now possible to delineate a proximal 1q deletion syndrome.     

Interstitial deletion 2q33.3-q34 in a boy with a phenotype resembling the Seckel syndrome

A boy presented at 5 weeks with a syndrome of pre- and postnatal growth retardation, microcephaly, muscular hypotonia, and facial anomalies resembling those seen in Seckel syndrome or microcephalic primordial dwarfism I. Analysis of prometaphase chromosomes, fluorescent in situ hybridization (FISH), and molecular studies showed the presence of a de novo chromosome 2 deletion that could be defined as del(2)(q33.3q34)pat. Parental chromosomes were normal, except for the presence of a paternal supernumerary marker identified by FISH as der(15). On follow-up of the patient during the next months length development appeared normal and the diagnosis of Seckel syndrome was withdrawn. Clinical findings of previously published cases with interstitial deletion of at least 2q33.3-q34, the deletion present in the propositus, are reviewed and include pre- and postnatal growth retardation, psychomotor retardation, microcephaly, micrognathia, and abnormal/low-set ears; findings also present in the propositus. These findings resemble those described in the Seckel syndrome. Noteworthy is the finding that 2/3 of the 60 reviewed cases originally reported as having Seckel syndrome apparently belong to a heterogeneous group of low birth weight microcephalic dwarfism I yet to be clearly defined. In these patients no chromosome 2q deletion has been reported so far. Retrospective analysis could show if a subgroup of these patients carry submicroscopic deletions at 2q33.3-q34. Alternatively, molecular analysis of this region may be warranted in newly diagnosed patients with Seckel syndrome- like manifestations. Am. J. Med. Genet. 71:479–485, 1997. © 1997 Wiley-Liss, Inc.     

Interstitial deletion 13q. Further delineation of the syndrome by clinical and high-resolution chromosome analysis of five patients

Five patients with interstitial deletion 13q are reported. High-resolution chromosome banding established the diagnosis in two cases and stated the exact breakpoints in three remaining cases. All parents had normal chromosomes. An unequal and so far unexplained sex ratio of previously published and present cases was found: M:F = 1:2.75. Moderate to severe growth retardation was prominent in all patients. The patients were followed with psychological tests and growth data for 3–10 years. Mild to moderate mental retardation was present. Considerable phenotypic similarities were found in two patients with del(13)(q21.33 q31.3) and one with del(13)(q14.3q22.3). Repeat ophthalmological examinations showed no evidence of retinoblastoma in a male with del(13)(ql3.1q21.1). In conclusion, the long-term study of five patients with interstitial deletion 13q, all evaluated with high-resolution banding, contributed to a more reliable mental and growth prognosis in such patients.     

Interstitial deletion of 6q21-q23 associated with split hand

We report on a 7-month-old boy with interstitial deletion of 6q21-q23 and split-hand defect. He died at 7 months. This is the fifth patient with distal limb anomaly associated with a rearrangement of 6q21 region, and supports previous suggestions that there may be candidate gene(s) for distal limb development in the 6q21 region. Am. J. Med. Genet. 69:268–270, 1997. © 1997 Wiley-Liss, Inc.     

Interstitial 6q deletion and Prader-Willi-like phenotype

A third case of an interstitial deletion of the long arm of chromosome 6 with clinical features mimicking Prader-Willi syndrome (PWS) is presented. Although preliminary clinical evaluation in each case suggested PWS, further review revealed that the features in all three cases are not completely compatible with the characteristic findings in Prader-Willi syndrome. Furthermore, the deletions in the three cases do not show a consistent region of overlap. Consequently, no particular band or region in 6q can be defined as associated widi obesity. However, our findings confirm the suggestion of Villa et al. in 1995, that individuals with a PWS phenotype who are cytogenetically and molecularly negative for a deletion of 15q11-q13 should be examined for a deletion of 6q.     

Interstitial deletion of chromosome 2q associated with ovarian dysgenesis

In the present report we describe a girl with mental retardation, Dandy-Walker malformation, craniofacial anomalies, cardiac defect, and ovarian dysgenesis associated with an interstitial deletion of chromosome 2. The interstitial deletion in the proband was associated with an apparently balanced translocation involving chromosomes 2 and 7 in the father.