Acrodermatitis enteropathica: an uncommon differential diagnosis in childhood - first description of a new sequence variant.

An 11-month-old boy was brought to our clinic with superinfected, sharply-defined, symmetrical, erythematous macules and vesicles, some with yellowish-brownish crusts, on the cheeks, fingers, and in the diaper region. The suspected impetigo contagiosa had failed to respond to both topical antiseptic therapy and systemic antibiotics. Because of the unusual clinical picture and course, we measured the serum zinc level. A significantly reduced level of 2 µmol/l (normal range 9.2-18.4 µmol/l) was identified. Initial skin lesions had appeared one week after weaning (5th week after birth). Since the age of 8 months the infant had also had recurrent diarrhea. Two weeks after zinc-histidine substitution, the diarrhea ceased and skin lesions slowly disappeared. Molecular genetic testing for the SLC39A4 (zinc transporter) gene revealed compound heterozygosity for the previously unidentified mutations c.1465_1474+4del (p.?) and c.295G>A (p.Ala99Thr). The parents are healthy heterozygous gene carriers. The same compound heterozygosity was later detected in the newborn brother of our patient shortly after birth. A zinc deficiency could therefore be identified and treated before symptoms occurred. The inherited autosomal recessive zinc transporter deficiency is termed acrodermatitis enteropathica. Lifelong zinc substitution is recommended. A differential diagnosis can be difficult because bacterial and fungal superinfection is common in zinc deficiency. Precise diagnosis requires testing family members for the gene.

Mild phenotype in two unrelated patients with a partial deletion of 21q22.2-q22.3 defined by FISH and molecular studies.

We describe two unrelated patients with cytogenetically visible deletions of 21q22.2-q22.3 and mild phenotypes. Both patients presented minor dysmorphic features including thin marfanoid build, facial asymmetry, downward-slanting palpebral fissures, depressed nasal bridge, small nose with bulbous tip, and mild mental retardation (MR). FISH and molecular studies indicated common deleted areas but different breakpoints. In patient 1, the breakpoint was fine mapped to a 5.2 kb interval between exon 5 and exon 8 of the ETS2 gene. The subtelomeric FISH probe was absent on one homologue 21 indicating a terminal deletion spanning approximately 7.9 Mb in size. In patient 2, the proximal breakpoint was determined to be 300-700 kb distal to ETS2, and the distal breakpoint 2.5-0.3 Mb from the 21q telomere, indicating an interstitial deletion sized approximately 4.7-7.3 Mb. The 21q- syndrome is rare and typically associated with a severe phenotype, but different outcomes depending on the size and location of the deleted area have been reported. Our data show that monosomy 21q of the area distal to the ETS2 gene, representing the terminal 7.9 Mb of 21q, may result in mild phenotypes comprising facial anomalies, thin marfanoid build, and mild MR, with or without signs of holoprosencephaly.