Juvenile Polyposis Syndrome in Israel is associated with a high mutation detection rate

Lior Katz1, Shlomi Cohen2, Elez Vainer1, Shanni Hegger3, Ilana Weintraub4, Ido Laish4, Gili Reznick-Levi5, Zohar Levi6, Rachel Belfer-Gingold6, Elizabeth Half5

1Hadassah Medical Center, Jerusalem, Israel. 2Dana Children’s hospital, Tel-Aviv, Israel. 3Ben-Gurion University, Beer-Sheva, Israel. 4Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel. 5Rambam Medical Center, Haifa, Israel. 6Rabin Medical Center, Petah-Tikva, Israel

Abstract

Objective: Juvenile polyposis syndrome (JPS) is characterized by a predisposition to develop multiple hamartomatous polyps in the gastrointestinal tract that carry risk of malignant transformation. We describe a series of JPS kindreds in Israel.

Methods: Retrospective data from 5 medical centers.

Results: 49 patients (36 families) were followed for a median of 5 years. 32\36 families (89%) were Jewish, with substantial representation of families from Muslims countries of the former Soviet Union (MFSU) (28.6%). Genetic tests were undertaken in 26 families (72%) and positive results achieved in 19 (73%). Having a mutation was not associated with a more severe phenotype. BMPR1A mutation was found in 12 families (63%), SMAD4 in 7 (37%). Rectal bleeding was the presenting symptom in 23/24 symptomatic patients (96%). Colonic involvement was recorded in 39 patients (80%), 14 (36%) with more than 50 polyps, and 12 (24.5%) underwent colectomies due to polyp burden. Twelve patients (24.5%) had gastric involvement and 4 underwent gastrectomies (25%). Five patients had small bowel (SB) polyps, all of whom had colonic involvement. Gastric and SB involvement were associated with Jewish families from MFSU (p=0.023 and p=0.002, respectively) regardless of mutation status. Gastrectomies and SB procedures were undertaken only in SMAD4 positive families. Cancer was reported in 2 patients.

Conclusions: JPS is highly represented among Jewish families from MFSU, and involves the UGI. High mutation rate is observed in the Israeli population, and SMAD4 positive have more severe UGI phenotype. Small bowel studies should be undertaken only after documentation of colonic involvement.

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