The partial 4q monosomy. Report of a 5-year-old boy with deletion 4q31.3 leads to 4qter

Distal Dorsal Dimelia: A Disturbance of Dorsal-Ventral Digit Development

PURPOSE

Congenital palmar nail (distal dorsal dimelia [dDD]) of the hand is a rare malformation most commonly affecting the little finger. The purpose of this report was to review the features and associations of this rare disorder and discuss the suspected underlying etiology in light of our current understanding of developmental biology.

METHODS

In this retrospective cohort study from 3 practices, we describe our collective experience and review the reported literature on this disorder both as an isolated condition and in conjunction with other anomalies.

RESULTS

We examined 15 fingers with dDD, 5 of which involved little fingers. We also found dDD in 6 cases with radial polydactyly (preaxial polydactyl type II [PPD2]) and in 1 case of cleft hand involving digits adjacent to the clefted web space (the index and middle fingers). Cases of little finger dDD were also associated with prominent clefting of the adjacent web space in 4 of 5 cases. All cases had stiffness of the interphalangeal joints and loss of palmar creases consistent with dorsalization of the palmar aspect of the digit. When combined with 63 fingers reported in the literature with dDD, 3 patterns were evident. The most common form occurred in little fingers (n = 50; 64%; dDDu). The next most common form was reported in association with cleft hands (n = 16; 21%; dDDc). Radial digits in association with either radial polydactyly (PPD2) or radial longitudinal deficiency were also susceptible to dDD (n = 12; 15%; dDDr).

CONCLUSIONS

Congenital dDD is a disturbance of terminal dorsal-ventral digit patterning. The distribution of this condition with little fingers, clefting, and altered radial digit formation (PPD2 or radial longitudinal deficiency), as well as recent genetic and animal studies, suggests that dDD and altered dorsal-ventral patterning are linked to abnormal apical ectodermal ridge boundary formation.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IV.

Hypercalciuria and kidney calcifications in terminal 4q deletion syndrome: Further evidence for a putative gene on 4q

We report a newborn girl with a de novo terminal 4q deletion (q31.3 --> qter) and a characteristic phenotype of minor facial anomalies, cleft palate, congenital heart defect, abnormalities of hands and feet, and postnatal onset of growth deficiency. Laboratory studies showed excessive urinary calcium excretion on standard milk formula and on oral calcium load. Blood measurements of parathyroid hormone, calcitonin, bicarbonate, calcium, phosphorus, magnesium, sodium, chlorine, potassium, and urinary measurements of phosphorus, magnesium, sodium, chlorine, potassium were normal for age. At 2 months of life, ultrasonography showed kidney calcifications. Clinical and laboratory data support the diagnosis of absorptive hypercalciuria or abnormal regulation of calcium-sensing receptors in the renal tubules. The evidence of hypercalciuria and kidney calcifications associated with 4q terminal deletion strengthens the hypothesis that a putative gene for hypercalciuria is located on the terminal segment of chromosome 4q.

Interstitial deletion 4q32-34 with ulnar deficiency: 4q33 may be the critical region in 4q terminal deletion syndrome

We report on an infant with Robin sequence; mild developmental delay; a left ulnar ray defect with absent ulna and associated metacarpals, carpals and phalanges; and a right ulnar nerve hypoplasia. He had a de novo interstitial deletion of 4q32-->q34. The critical region involved in the 4q terminal deletion syndrome may be 4q33. This conclusion was suggested by showing that del(4)(q31qter), del(4)(q32qter), and del(4)(q33qter) result in a similarly severe phenotype. In addition, we propose that genes for distal arm development, in particular for development of the left ulnar ray, central nervous system development, and cleft lip and palate, may be located at 4q33.

Terminal deletion 4q in a severely retarded boy

We report a boy with a de novo terminal deletion of chromosome 4q, (q31----qter) and compare him to 17 previously reported cases with the same anomaly. This case contributes further to the delineation of the del(4)(q31) phenotype, which seems to be clinically recognizable.

Interstitial and terminal deletions of the long arm of chromosome 4: further delineation of phenotypes

We reviewed 45 patients with a deletion of the long arm of chromosome 4. Forty-one were previous reports (25 terminal deletions and 16 interstitial deletions) and 4 are new cases with terminal deletions. Of the 29 patients with terminal deletions, 18 with deletion at 4q31 and 4 at 4q32----qter had an identifiable phenotype consisting of abnormal skull shape, hypertelorism, cleft palate, apparently low-set abnormal pinnae, short nose with abnormal bridge, virtually pathognomonic pointed fifth finger and nail, congenital heart and genitourinary defects, moderate-severe mental retardation, poor postnatal growth, and hypotonia. Six patients with a deletion at 4q33 and one patient with deletion 4q34 were less severely affected. In general, patients with various interstitial deletions proximal to 4q31 had a phenotype that was less specific, although mental retardation and minor craniofacial anomalies were also present. There were 3 patients with piebaldism and one with Rieger syndrome. We conclude that terminal deletion of chromosome 4q (4q31----qter) appears to produce a distinctive malformation (MCA/MR) syndrome in which the phenotype correlates with the amount of chromosome material missing and which differs from the more variable phenotype associated with interstitial deletions of 4q.

A terminal deletion of the long arm of chromosome 4 [46,XX,del(4)(q33)] in an infant with phenotypic features of Williams syndrome

A female infant with peripheral pulmonary artery stenosis, growth retardation, and developmental delay was noticed to have facial features consistent with a diagnosis of Williams syndrome. Chromosome analysis revealed a deletion of the terminal portion of the long arm of chromosome 4 (4q33----qter). This is the seventh reported case of this chromosome disorder. It is possible that this chromosome region is specific for the Williams syndrome phenotype but it is more likely that the syndrome is heterogeneous. Chromosome analysis should be performed in all suspected cases with particular attention to the long arm of chromosome 4.

Severe limb malformations in 4p deletion

Severe limb anomalies with radial aplasia and hypodactylia are reported in a male newborn with 4p deletion syndrome. In apparent contradiction with previous reports, this finding indicates that the radial aplasia, as frequently observed in patients with ring chromosome 4, seems to be more likely related to the 4p deletion, rather than to the 4q deletion.