Prenatal testing in a fetus at risk for autosomal dominant polycystic kidney disease and autosomal recessive junctional epidermolysis bullosa with pyloric atresia

Recent advances in the cell biology of polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a significant familial disorder, crossing multiple ethnicities as well as organ systems. The goal of understanding and, ultimately, curing ADPKD has fostered collaborative efforts among many laboratories, mustered on by the opportunity to probe fundamental cellular biology. Here we review what is known about ADPKD including well-accepted data such as the identification of the causative genes and the fact that PKD1 and PKD2 act in the same pathway, fairly well-accepted concepts such as the "two-hit hypothesis," and somewhat confusing information regarding polycystin-1 and -2 localization and protein interactions. Special attention is paid to the recently discovered role of the cilium in polycystic kidney disease and the model it suggests. Studying ADPKD is important, not only as an evaluation of a multisystem disorder that spans a lifetime, but as a testament to the achievements of modern biology and medicine.

Generalized gravis junctional epidermolysis bullosa: case report, laboratory evaluation, and review of recent advances

A full-term infant with junctional epidermolysis bullosa (JEB) is described. The distribution and morphologic characteristics of generalized blistering in areas of pressure in conjunction with perioral and perinasal granulation tissue suggested the diagnosis of generalized gravis (Herlitz) JEB. The family history was consistent with autosomal recessive inheritance. Electron microscopy demonstrated a subepidermal cleft arising in the lamina lucida with hemidesmosomal hypoplasia, findings consistent with gravis JEB. Immunofluorescent antigenic mapping localized laminin and type IV collagen exclusively to the blister base and weak reactivity of bullous pemphigold antigen to both the roof and the base. Type VII collagen (LH 7:2 epitope) was detected solely at the base of the cleavage plane, and abnormal staining of laminin 5 (kalinin, GB3, nicein) and 19-DEJ-1 antigen was observed. The patient died of sepsis at age 3 months. DNA extracted from cultured keratinocytes for molecular genetic analysis demonstrated a mutation with the LAMB3 gene encoding the beta 3 chain of laminin 5. We present the clinical and laboratory findings and briefly review recent advances in the diagnosis and management of JEB.

Gene linkage analysis and DNA based detection of autosomal dominant polycystic kidney disease (ADPKD) in a newborn infant. Case report

Bilateral polycystic kidneys were detected by ultrasound at 23 weeks gestation in a male fetus. Bilateral renal cysts were subsequently also found in the asymptomatic propositus' mother and grandmother, suggesting the diagnosis of autosomal dominant polycystic kidney disease (ADPKD). The renal ultrasonograms showed cortical cysts with normal or decreased-sized kidneys. Renal function was normal. Seven available members of the family were genotyped for flanking DNA markers tightly linked to the PKD1 gene on chromosome 16p, and for a polymorphism close to a second putative disease gene (PKD2) on chromosome 2. The genetic linkage approach allowed us to detect with a high degree of accuracy the ADPKD1 at risk chromosome in the three patients, as well as in a 28-year-old unaffected female. This report illustrates the feasibility and the usefulness of recent molecular genetic strategies for diagnostic purposes in ADPKD, especially when clinical and radiological data are atypical. Furthermore, it also confirms that early or very early onset forms of the disease are not uncommon, and should be considered in the differential diagnosis of childhood cystic disease.